162: Deep Fungal Infections Flashcards
(276 cards)
1
Q
What are the two distinct groups of deep fungal infections?
A
- Subcutaneous mycoses: Largely confined to the tropics and subtropics, often present with signs of skin involvement.
- Systemic mycoses: Opportunistic infections, primarily affecting immunocompromised patients, and include respiratory tract infections like histoplasmosis and coccidioidomycosis.
2
Q
What is sporotrichosis and what causes it?
A
Sporotrichosis is a subcutaneous or systemic fungal infection caused by the dimorphic fungus Sporothrix. It has five different species that vary in geographic distribution, including Sporothrix schenckii and Sporothrix brasiliensis.
3
Q
What are the clinical features of subcutaneous mycoses?
A
Cutaneous findings:
- Subcutaneous form: More common than systemic form, with two main forms:
- Lymphangitic: Develops on exposed skin sites, starts as a dermal nodule that ulcerates and causes secondary nodules along lymphatics.
- Fixed: Localized to one site, often forming granulomas and satellite nodules.
Noncutaneous findings:
- Systemic form: Much rarer, can develop anywhere, often presenting as chronic lung nodules, arthritis, or meningitis.
4
Q
What are the best sources of diagnostic material for sporotrichosis?
A
The best sources of diagnostic material for sporotrichosis include:
- Smears
- Exudates
- Biopsies
Sporothrix is rarely seen in direct microscopic examination due to its low numbers in tissue, but it can be isolated readily on Sabouraud agar.
5
Q
What is the significance of the ‘asteroid body’ in sporotrichosis?
A
The ‘asteroid body’ is a characteristic finding in sporotrichosis, where fungal cells are surrounded by an eosinophilic refractile fringe. This phenomenon may occur with other infectious organisms as well, but it is a notable feature in the diagnosis of sporotrichosis.
6
Q
A gardener develops a dermal nodule on the hand that ulcerates and spreads along the lymphatics. What is the diagnosis, and what is the first-line treatment?
A
The diagnosis is Sporotrichosis. The first-line treatment is Itraconazole (200 mg daily). Potassium iodide is a cheaper alternative for cutaneous types.
7
Q
What is the common characteristic of subcutaneous mycoses?
A
They are usually sporadic infections caused by fungi introduced directly into the dermis or subcutaneous tissue.
8
Q
What are the common sites of infection for sporotrichosis?
A
Most frequently in the dermis or subcutis.
9
Q
What is a key diagnostic feature of cutaneous lesions in sporotrichosis?
A
The scarcity of organisms in tissue.
10
Q
What are the two main forms of cutaneous findings in subcutaneous mycoses?
A
Lymphangitic and fixed forms.
11
Q
What is the most common form of sporotrichosis?
A
The lymphangitic form, which develops on exposed skin sites.
12
Q
What are the common noncutaneous findings in systemic sporotrichosis?
A
Chronic lung nodules, arthritis, and meningitis.
13
Q
What is the appearance of the fungus in sporotrichosis under microscopic examination?
A
Small (3 to 5 μm) cigar-shaped or oval yeasts, sometimes surrounded by an eosinophilic fringe forming an asteroid body.
14
Q
What is mycetoma and how is it characterized?
A
Mycetoma is a chronic localized infection caused by different species of fungi or actinomycetes, characterized by the formation of grains which are aggregates of the causative organisms found within abscesses.
15
Q
What are the common clinical features of mycetoma?
A
-
Cutaneous Features:
- Most commonly affects the foot, lower leg, or hand; head or back involvement may also occur.
- The earliest stage presents as a firm, painless nodule that spreads slowly, developing papules and draining sinus tracts.
-
Complications:
- Local tissue swelling and chronic sinus formation.
- Bone involvement can distort and deform the original site of infection.
- Seldom painful except in late stages.
16
Q
What is the management approach for mycetoma?
A
The management of mycetoma typically includes:
1. Antifungal Chemotherapy:
- Itraconazole (200 mg daily)
- Terbinafine (250 mg daily)
- IV Amphotericin B for deep infections
- Voriconazole or Posaconazole (limited experience)
2. Potassium Iodide (saturated solution):
- Cheaper alternative, effective for cutaneous types.
- Dosage: 4 to 6 mL three times daily, continued for 3 to 4 weeks after clinical cure.
- Side effects may include hypersalivation and nausea.
17
Q
What are the epidemiological factors associated with mycetoma?
A
Epidemiological factors associated with mycetoma include:
- Mainly found in the dry tropics with low annual rainfall.
- Sporadic infections that are seldom common.
- Occasionally reported from temperate climates, with Scedosporium apiospermum being the most common organism in these cases.
18
Q
What is the typical clinical course of mycetoma with treatment?
A
It resolves readily with treatment.
19
Q
What is the role of potassium iodide in the management of mycetoma?
A
It is a cheaper alternative effective in the cutaneous types, but it is unpalatable.
20
Q
What organisms are responsible for actinomycetomas?
A
Species of aerobic actinomycetes, primarily Nocardia species.
21
Q
What are the common clinical features of Chromoblastomycosis?
A
- Initial site of infection: feet, legs, arms, or upper trunk
- Initial lesion: warty papule that expands slowly over months or years
- May develop into a plaque-like lesion with an atrophic center
- Verrucous form spreads slowly and locally
- Lesions may be thick and can develop secondary bacterial infections
22
Q
What are the common causative agents of Chromoblastomycosis?
A
- Phialophora verrucosa
- Fonsecaea pedrosoi
- Fonsecaea compactum
- Wangiella dermatitidis
- Cladophialophora carrionii
23
Q
What are the complications associated with Chromoblastomycosis?
A
- Local lymphedema leading to elephantiasis
- Squamous cell carcinomas in some chronic lesions
24
Q
What laboratory tests are used for diagnosing Chromoblastomycosis?
A
- Sclerotic or muriform fungal cells seen in skin scrapings
- Gross appearance in culture: black colonies with a downy surface
- Cultural identification based on sporulation types
- Biopsy of lesions to observe pathologic changes and muriform cells
25
A patient presents with a firm, painless nodule on the foot that has developed into draining sinus tracts. What is the likely diagnosis, and what are the key diagnostic features?
The likely diagnosis is Mycetoma. Key diagnostic features include grains discharged from sinus tracts, which can be black, red, or pale/white. Direct microscopy and culture are used for identification.
26
A patient presents with verrucous skin lesions and local lymphedema. What is the diagnosis, and what complications should be monitored?
The diagnosis is Chromoblastomycosis. Complications include elephantiasis and squamous cell carcinoma in chronic lesions.
27
A patient presents with a chronic granulomatous response and pigmented fungal cells in skin scrapings. What is the diagnosis, and what is the treatment?
The diagnosis is Chromoblastomycosis. Treatment includes Itraconazole (200 mg daily) or Terbinafine (250 mg daily).
28
What complications can arise from Chromoblastomycosis?
Local lymphedema leading to elephantiasis and squamous cell carcinomas in some chronic lesions.
29
What is the diagnosis and treatment for a patient with a chronic granulomatous response and pigmented fungal cells in skin scrapings?
The diagnosis is Chromoblastomycosis. Treatment includes Itraconazole (200 mg daily) or Terbinafine (250 mg daily).
30
What is the likely diagnosis and causative organism for a chronic, painless nodule on the chest wall?
The likely diagnosis is Actinomycetoma caused by Nocardia species.
31
What is the diagnosis and causative organism for a chronic, painless nodule on the foot with black grains discharged from sinus tracts?
The diagnosis is Mycetoma caused by fungi.
32
What is the diagnosis and causative organism for a chronic, painless nodule on the hand with pale grains discharged from sinus tracts?
The diagnosis is Mycetoma caused by either fungi or actinomycetes.
33
What is the diagnosis and causative organism for a chronic, painless nodule on the foot with red grains discharged from sinus tracts?
The diagnosis is Mycetoma caused by actinomycetes.
34
What is the diagnosis and causative organism for a chronic, painless nodule on the foot with white grains discharged from sinus tracts?
The diagnosis is Mycetoma caused by either fungi or actinomycetes.
35
What is Chromoblastomycosis and what causes it?
A chronic fungal infection of the skin and subcutaneous tissues caused by pigmented (dematiaceous) fungi that are implanted into the dermis from the environment.
36
What are the common fungi associated with Chromoblastomycosis?
Phialophora verrucosa, Fonsecaea pedrosoi, Fonsecaea compactum, Wangiella dermatitidis, and Cladophialophora carrionii.
37
What are the initial clinical features of Chromoblastomycosis?
The initial site of infection is often the feet, legs, arms, or upper trunk, presenting as a warty papule that expands slowly over months or years.
38
What laboratory tests are used for diagnosing Chromoblastomycosis?
Sclerotic or muriform fungal cells can be seen in skin scrapings, and gross macroscopic appearance in culture shows black colonies with a downy surface.
39
What is the typical pathology observed in Chromoblastomycosis?
Lesions should be biopsied showing mixed granulomatous response, small neutrophil abscesses, and the presence of muriform cells.
40
What is the management approach for fungal causes of mycetoma?
Management includes antifungal medications such as Ketoconazole, Itraconazole, and Voriconazole, with responses to chemotherapy being unpredictable.
41
What is the differential diagnosis for conditions similar to mycetoma?
Chronic bacterial or tuberculous osteomyelitis and Actinomycosis are similar but develop close to certain sites where the causative organisms are sometimes commensal.
42
What are the key laboratory testing methods for diagnosing mycetoma grains?
The key laboratory testing methods for diagnosing mycetoma grains include:
1. **Diagnosis**: Discharge from sinus tracts, obtained by removing the surface crust from a pustule or sinus tract.
2. **Microscopy**: Direct microscopy to identify the composition of grains (actinomycete or fungal filaments).
3. **Culture Isolation**: Requires isolation in culture using various media and incubation conditions.
4. **PCR**: Specific primers can be used for identification.
5. **Serology**: Helpful in some cases as a guide to therapeutic response.
43
What are the clinical features of chromoblastomycosis?
The clinical features of chromoblastomycosis include:
1. **Initial Site of Infection**: Typically occurs on the feet, legs, arms, or upper trunk.
2. **Lesion Characteristics**: Initial lesion often appears as a warty papule that expands slowly over months or years.
3. **Verrucous Form**: More common, spreads slowly and locally, may develop thick lesions with secondary bacterial infections.
4. **Satellite Lesions**: Local extensions of the infection produced by scratching.
5. **Complications**: Can lead to local lymphedema, elephantiasis, and squamous cell carcinomas in chronic cases.
44
What is the management approach for fungal causes of mycetoma?
The management approach for fungal causes of mycetoma includes:
1. **Antifungal Therapy**:
- Ketoconazole 200 mg
- Itraconazole 200 mg
- Voriconazole 200 to 400 mg
2. **Trial Therapy**: With Griseofulvin or Terbinafine for other fungal infections.
3. **Combination Antibiotics**: For actinomycetomas, options include:
- Dapsone with Streptomycin
- SMX-TMP + Rifampin or Streptomycin
- Amikacin, Moxifloxacin, or Imipenem for recalcitrant Nocardia.
4. **Surgical Intervention**: In advanced cases, surgery is often necessary, usually amputation, and in defined lesions, surgical dissection following antifungal therapy can yield excellent results.
45
What are the epidemiological factors associated with chromoblastomycosis?
Epidemiological factors associated with chromoblastomycosis include:
1. **Environmental Sources**: Isolated from wood, plant debris, or soil.
2. **Causative Organisms**: Primarily caused by Fonsecaea pedrosoi and Cladophialophora carrionii.
3. **Tissue Injury**: Infection often occurs through tissue injury.
4. **Geographic Distribution**: Found sporadically in Central and South America, the Caribbean, Africa (especially Madagascar), South Asia, Australasia, and Japan.
5. **Demographics**: Most frequently reported in male rural workers.
46
What are the main treatments for extensive lesions in chromoblastomycosis?
- **Amphotericin B** and **flucytosine**
- **Itraconazole** and **terbinafine**
- These combinations are used as extensive lesions respond poorly to conventional treatment.
47
What is the characteristic histopathology of Phaeohyphomycosis?
- Cyst wall consists of **palisades of macrophages** and other inflammatory cells surrounded by a **fibrous capsule**.
- Fungal hyphae are found in the macrophage zone.
- Fungi in tissue lesions are usually **pigmented**, but not always.
- **Hyalohyphomycotic cysts**: lesions caused by **nonpigmented fungi**.
48
What is the main treatment for Lobomycosis?
- The main treatment for Lobomycosis is **surgical removal**.
- Antifungal drugs are **NOT effective** for this infection.
49
What are the two main varieties of Subcutaneous Mucormycosis and their characteristics?
| Variety | Characteristics |
|---------|----------------|
| 1. Basidiobolus ranarum | - Common in children
- Found in plant debris and intestinal tracts of reptiles and amphibians
- Lesions present as a firm, slowly spreading, woody cellulitis around limb girdle sites |
| 2. Conidiobolus coronatus | - Seen in adults
- Isolated from soil, plant debris, and some insects
- Early infection starts in the inferior turbinates of the nose, spreading to the central part of the face, causing severe deformity of the nose, lips, and cheeks.
- Swelling is hard and painless |
50
What is the histopathology of Rhinosporidiosis?
- Large **sporangia** or **spore sacs** in different phases of development are readily seen.
- The infection causes **polyps** affecting the mucous membranes, particularly the nasal mucosa.
51
What is the diagnosis and main treatment for a patient from a tropical region with keloid-like skin lesions?
The diagnosis is Lobomycosis. The main treatment is surgical removal, as antifungal drugs are not effective.
52
What is the diagnosis and causative organism for a chronic, firm swelling around the limb girdle?
The diagnosis is Subcutaneous Mucormycosis caused by Basidiobolus ranarum.
53
What is the diagnosis and treatment for a chronic, woody cellulitis around the limb girdle?
The diagnosis is Subcutaneous Mucormycosis caused by Basidiobolus ranarum. Treatment includes Ketoconazole (400 mg daily) or Itraconazole (100-200 mg daily).
54
What is the diagnosis and causative organism for a chronic, firm swelling on the face causing deformity?
The diagnosis is Conidiobolomycosis caused by Conidiobolus coronatus.
55
What is the diagnosis and causative organism for a chronic, firm swelling on the nose and cheeks?
The diagnosis is Conidiobolomycosis caused by Conidiobolus coronatus.
56
What is the main treatment for chromoblastomycosis?
Itraconazole, 200 mg daily, and Terbinafine, 250 mg daily.
57
What is the characteristic feature of Phaeohyphomycosis?
Formation of subcutaneous inflammatory cysts or plaques.
58
What is the common cause of Lobomycosis?
The fungus Lacazia loboi.
59
What are the two main varieties of Subcutaneous Mucormycosis?
1) Basidiobolus ranarum, 2) Conidiobolus coronatus.
60
What is the treatment for Subcutaneous Mucormycosis?
Ketoconazole (400 mg daily) and Itraconazole (100 to 200 mg daily).
61
What is the main site affected by Rhinosporidiosis?
Nasal mucosa.
62
What is a common histopathological finding in Phaeohyphomycosis?
Cyst wall consists of palisades of macrophages surrounded by a fibrous capsule.
63
What is the clinical course of chromoblastomycosis?
No spontaneous remission.
64
What is the main treatment for Rhinosporidiosis?
Surgical excision is the only treatment.
65
What are the main treatments for extensive lesions caused by chromoblastomycosis, and how do they differ from conventional treatments?
Main treatments for extensive lesions include:
1. **Amphotericin B** and **flucytosine**
2. **Itraconazole** and **terbinafine**
These combinations are used because extensive lesions respond poorly to conventional treatment, which typically involves single antifungal agents.
66
What is the clinical significance of the histopathological findings in Phaeohyphomycosis?
Histopathological findings in Phaeohyphomycosis include:
- **Cyst wall**: Composed of palisades of macrophages and inflammatory cells surrounded by a fibrous capsule.
- **Fungal hyphae**: Found within the macrophage zone, often pigmented.
- **Hyalohyphomycotic cysts**: Caused by nonpigmented fungi.
These findings indicate a chronic inflammatory response and help differentiate it from other fungal infections.
67
How does the treatment approach for Lobomycosis differ from other fungal infections, and what is the main treatment?
Lobomycosis is characterized by:
- **Inability to culture** the organism in vitro.
- **Antifungal drugs** are NOT effective.
The main treatment is **surgical removal** of the lesions, which is distinct from other fungal infections.
68
What are the two main varieties of Subcutaneous Mucormycosis?
**1. Basidiobolus ranarum**:
- Common in children.
- Lesions present as a firm, slowly spreading, woody cellulitis around limb girdle sites.
**2. Conidiobolus coronatus**:
- Seen in adults.
- Early infection starts in the inferior turbinates of the nose, spreading to the central part of the face, causing severe deformity.
69
What is the significance of the histopathological findings in Rhinosporidiosis?
Histopathological findings in Rhinosporidiosis include:
- **Large sporangia or spore sacs** in various developmental phases.
These findings are significant as they help confirm the diagnosis of Rhinosporidiosis, which is associated with exposure to water. The primary treatment is **surgical excision**, which is the only effective treatment.
70
What are the two main varieties of systemic mycoses?
**1. Opportunistic mycoses**:
- Chief opportunistic systemic mycoses include systemic or deep candidiasis, aspergillosis, and systemic zygomycosis.
- Affect patients with severe underlying disease states.
- Skin involvement is not common.
**2. Endemic respiratory mycoses**:
- Includes histoplasmosis (classic and African types), blastomycosis, coccidioidomycosis, paracoccidioidomycosis, and infections due to Talaromyces marneffei.
71
What infections are caused by Talaro myces marneffei?
Infections due to Talaro myces marneffei.
72
How are clinical manifestations affected in infections due to Talaro myces marneffei?
Clinical manifestations are affected by the underlying immunodeficiency state of the patient.
73
What is the primary route of infection for endemic respiratory mycoses?
The usual route of infection for endemic respiratory mycoses is the **lung**.
74
What are the two types of human infections caused by Histoplasma?
1. **Classic or Small-Form Histoplasmosis**:
- Caused by H. capsulatum var. capsulatum.
- Produces cells from 2 to 5 µm in diameter.
2. **African Histoplasmosis**:
- Caused by H. capsulatum var. duboisii.
- Produces cells of 10 to 15 µm in diameter.
75
What is the clinical significance of Histoplasmosis?
Histoplasmosis starts as a **pulmonary infection**, which is often asymptomatic and heals spontaneously in most cases. It can lead to symptomatic respiratory tract infections and may progress to acute or chronic pulmonary histoplasmosis, with potential dissemination affecting the skin or mucous membranes.
76
How does Cryptococcosis relate to systemic mycoses?
Cryptococcosis shares clinical and pathologic features of both opportunistic and endemic mycoses, primarily affecting untreated AIDS patients. It is characterized by its ability to cause respiratory systemic mycoses.
77
What is the initial portal of entry for systemic mycoses?
Usually a deep site such as the lung, GI tract, or paranasal sinuses.
78
What are the two main varieties of systemic mycoses?
Opportunistic mycoses and endemic respiratory mycoses.
79
What are some examples of opportunistic mycoses?
Systemic candidiasis, aspergillosis, and systemic zygomycosis.
80
What are the three types of systemic mycoses?
Systemic mycoses include candidiasis, aspergillosis, and systemic zygomycosis.
81
What factors predispose patients to different mycoses?
Different underlying conditions and disease states.
82
What are endemic respiratory mycoses?
Endemic respiratory mycoses include histoplasmosis, blastomycosis, coccidioidomycosis, paracoccidioidomycosis, and infections due to Talaromyces marneffei.
83
How does cryptococcosis relate to systemic mycoses?
It shares clinical and pathologic features of both opportunistic and endemic mycoses, mainly seen in untreated AIDS patients.
84
What is histoplasmosis caused by?
The dimorphic fungus Histoplasma capsulatum.
85
What are the two types of human infections caused by Histoplasma?
Classic or small-form histoplasmosis and African histoplasmosis.
86
What is the size range of cells produced by H. capsulatum var. capsulatum?
2 to 5 µm in diameter.
87
What is the significance of the intradermal skin test for histoplasmosis?
It is the only evidence of exposure to the fungus.
88
What are the two main varieties of systemic mycoses and how do they differ in terms of patient predisposition?
**Opportunistic Mycoses**:
- Affect patients with severe underlying disease states.
- Chief examples include systemic candidiasis, aspergillosis, and systemic zygomycosis.
- Different underlying conditions predispose to different mycoses.
- Skin involvement is not common.
**Endemic Respiratory Mycoses**:
- Include histoplasmosis, blastomycosis, coccidioidomycosis, and others.
- Clinical manifestations are affected by the underlying immunodeficiency state of the patient.
- May affect otherwise healthy individuals.
89
What is the clinical significance of distinguishing between classic and African histoplasmosis?
It helps in understanding the epidemiology and treatment options for different forms of histoplasmosis.
90
What is Classic Histoplasmosis?
Classic Histoplasmosis (H. capsulatum var. capsulatum) produces cells from 2 to 5 µm in diameter. Typically presents as a pulmonary infection that is often asymptomatic and heals spontaneously.
91
What is African Histoplasmosis?
African Histoplasmosis (H. capsulatum var. duboisii) produces larger cells of 10 to 15 µm in diameter. May present with more severe clinical manifestations compared to classic histoplasmosis. Important for serodiagnosis and treatment approaches.
92
How does Cryptococcosis relate to systemic mycoses, particularly in untreated AIDS patients?
Cryptococcosis shares clinical and pathologic features with both opportunistic and endemic mycoses. It is primarily seen in untreated AIDS patients, highlighting the blurred distinction between these two categories of systemic mycoses. This emphasizes the need for careful diagnosis and treatment in immunocompromised individuals.
93
What are the primary clinical features of Acute Pulmonary Histoplasmosis?
Patients often exposed to large quantities of spores from caves or bird-infested areas. Symptoms include cough, chest pain, fever, joint pains, and rash (toxic erythema, erythema multiforme, or erythema nodosum). Skin rashes are uncommon, occurring in less than 15% of patients. Chest X-ray may show diffuse mottling that can calcify over time.
94
What distinguishes Chronic Pulmonary Histoplasmosis from Acute Pulmonary Histoplasmosis?
Chronic Pulmonary Histoplasmosis occurs in adults and presents with pulmonary consolidation and cavitation, resembling tuberculosis. Skin involvement is not seen in Chronic Pulmonary Histoplasmosis.
95
What is the significance of the Histoplasmin skin test in diagnosing Histoplasmosis?
The Histoplasmin skin test is an epidemiologic tool that is of no help in diagnosing disseminated histoplasmosis, as it often yields negative results in such cases.
96
What are the common diagnostic methods for Histoplasmosis?
Diagnosis is established by identifying small intracellular yeast-like cells of Histoplasma in sputum, peripheral blood, bone marrow, or biopsy specimens.
## Footnote
Culture confirmation is necessary, with growth as a mold at room temperature. Serology is useful, with rising complement-fixation titers indicating dissemination and the presence of antibodies correlating with active infection.
97
What are the clinical implications of Acute Progressive Disseminated Histoplasmosis?
It involves widespread dissemination to organs such as the liver, spleen, lympho-reticular system, and bone marrow.
## Footnote
Symptoms include progressive weight loss, fever, anemia, and hepatosplenomegaly, particularly in untreated AIDS patients. Skin lesions may develop, and diffuse micronodular pulmonary infiltrates may be present.
98
What is the diagnosis for a patient presenting with molluscum-like lesions and a history of HIV?
The diagnosis is Histoplasmosis. Diagnostic tests include identifying small intracellular yeast-like cells in biopsy specimens and serologic tests for Histoplasma antigens.
99
What is the diagnosis for a patient with a chronic cough and cavitation on chest X-ray resembling tuberculosis?
The diagnosis is likely Histoplasmosis.
100
What fungal infection should be considered with a non-chest X-ray resembling tuberculosis?
The fungal infection to consider is Chronic Pulmonary Histoplasmosis.
## Footnote
Treatment includes Itraconazole (200-400 mg daily).
101
What is the likely diagnosis for a patient with a chronic, indurated ulcer on the skin with locally lymphadenopathy?
The likely diagnosis is Primary Cutaneous Histoplasmosis caused by Histoplasma capsulatum.
102
What is the primary mode of transmission for Histoplasmosis?
Acquired by inhalation of spores from contaminated soil or bird droppings.
103
What are the common clinical features of Acute Pulmonary Histoplasmosis?
Cough, chest pain, fever, joint pains, and rash, with toxic erythema or erythema multiforme.
104
What distinguishes Chronic Pulmonary Histoplasmosis from Acute Pulmonary Histoplasmosis?
Chronic Pulmonary Histoplasmosis presents with pulmonary consolidation and cavitation, resembling tuberculosis.
105
What is a significant risk factor for developing Acute Progressive Disseminated Histoplasmosis?
Being an untreated AIDS patient.
106
What is the role of the Histoplasmin skin test in diagnosing Histoplasmosis?
It is of no help in diagnosing disseminated histoplasmosis.
107
What laboratory method is used to confirm the diagnosis of Histoplasmosis?
Identifying small intracellular yeast-like cells of Histoplasma in sputum, blood, or biopsy specimens.
108
What are the characteristics of H. capsulatum in tissue pathology?
It is an intracellular parasite seen in macrophages, with cells small (2 to 4 µm) and oval in shape with small buds.
109
What is a common differential diagnosis for Histoplasmosis?
Other fungal infections or granulomatous diseases.
110
What is a common differential diagnosis for Histoplasmosis?
Other deep mycoses such as T. marneffei, Blastomyces, and Cryptococcus.
111
What is the significance of serology in diagnosing Histoplasmosis?
Rising complement-fixation titer indicates dissemination and presence of antibodies correlates with active infection.
112
What are the clinical features of Acute Progressive Disseminated Histoplasmosis and its common manifestations in untreated AIDS patients?
Acute Progressive Disseminated Histoplasmosis is characterized by:
- Widespread dissemination to organs such as the liver, spleen, lymphoreticular system, and bone marrow.
- Symptoms include progressive weight loss, fever, anemia, and hepatosplenomegaly.
- In untreated AIDS patients, skin lesions may develop, presenting as papules, small nodules, or molluscum-like lesions that can evolve into shallow ulcers, which are common in HIV+ individuals.
- Diffuse micronodular pulmonary infiltrates may also develop.
113
How is the diagnosis of Histoplasmosis established and what are the key diagnostic methods?
The diagnosis of Histoplasmosis is established through:
1. Identification of small intracellular yeast-like cells of Histoplasma in:
- Sputum
- Peripheral blood
- Bone marrow
- Biopsy specimens
2. Culture confirmation, where the organism grows as a mold at room temperature, producing white, cottony colonies on Sabouraud glucose agar.
3. Demonstration of ribosomal RNA using a DNA probe for confirmation.
4. Serological tests to detect circulating Histoplasma antigens, particularly useful in AIDS patients.
5. PCR-based molecular diagnostic methods available in some centers.
114
What are the differential diagnoses to consider when diagnosing Histoplasmosis, particularly in tropical regions?
Consider the following differential diagnoses:
- T. marneffei
- Small forms of Blastomyces
- Cryptococcus
- Leishmania sp.
- In tropical regions, Kala azar is also an important differential diagnosis due to similar clinical presentations.
115
What are the common sites of infection for African histoplasmosis?
The most common sites of infection for African histoplasmosis are:
- Skin
- Bone
- Lymph nodes
- Other organs, including the lungs.
116
What is the significance of H. capsulatum var. duboisii in African histoplasmosis?
H. capsulatum var. duboisii is significant because it is different from the smaller capsulatum forms, measuring 10 to 15 µm in diameter, slightly pear-shaped, and clustered in giant cells. Histoplasma serology is often negative in African histoplasmosis.
117
What is the recommended treatment for disseminated or localized forms of African histoplasmosis?
The recommended treatment includes:
1. Itraconazole (200 to 400 mg daily) - highly effective for long-term suppressive therapy in AIDS patients after primary therapy.
2. For widespread and severe infections, IV Amphotericin B (up to 1 mg/kg daily) is used as an alternative.
3. Posaconazole and Voriconazole may be effective in some cases.
118
What are the clinical features of North American blastomycosis?
The clinical features of North American blastomycosis include:
- Subclinical form of infection
- Primary cutaneous blastomycosis.
119
What is primary cutaneous blastomycosis?
A rare form of infection that follows trauma to the skin, presenting as an erythematous, indurated area with a chancre.
120
What are the symptoms of pulmonary blastomycosis?
May be asymptomatic or present with low-grade fever, chest pain, cough, and hemoptysis.
121
What characterizes disseminated blastomycosis?
Skin lesions are common, may ulcerate, and can affect almost any organ, with common sites including bone, the epididymis, and the adrenal gland.
122
How is the diagnosis of blastomycosis confirmed?
The diagnosis is confirmed through:
- Finding the fungus in KOH mounts of pus, skin scrapings, or sputum as thick-walled, rounded, refractile, spherical cells with broad-based buds.
- Culture growth as a mycelial fungus at room temperature, producing small, rounded, or pear-shaped conidia.
- At higher temperatures, it produces yeast forms with characteristic buds.
- Precipitating antibodies to B. dermatitidis are often present in infected patients' sera.
123
What is the likely fungal infection for a patient with chronic cough, weight loss, and nodular lesions on chest X-ray?
The likely fungal infection is Chronic Pulmonary Blastomycosis. Treatment includes Itraconazole (200-400 mg daily).
124
What is the likely diagnosis for a patient with chronic pulmonary infection and multiple skin lesions?
The likely diagnosis is Disseminated Blastomycosis caused by Blastomyces dermatitidis.
125
What is the causative agent of African histoplasmosis?
Histoplasma capsulatum var. duboisii.
126
What are the common sites of infection for African histoplasmosis?
Skin and bone, although lymph nodes and other organs may also be affected.
127
What is histoplasmosis?
A disease affecting skin and bone, although lymph nodes and other organs may be affected.
128
What is the typical presentation of African histoplasmosis?
Small papules resembling molluscum contagiosum, cold abscesses, draining sinuses, or ulcers.
129
How is African histoplasmosis diagnosed?
By culture and direct microscopy or histopathology.
130
What is the treatment of choice for African histoplasmosis?
Itraconazole.
131
What is the primary causative agent of North American blastomycosis?
Blastomyces dermatitidis.
132
What are common sites affected by North American blastomycosis?
Lungs, skin, bones, and other sites.
133
What is a common clinical feature of North American blastomycosis?
It has a subclinical form of the infection.
134
What is the typical diagnostic finding for blastomycosis in KOH mounts?
Thick-walled, rounded, refractile, spherical cells with broad-based buds.
135
What does the prognosis for blastomycosis depend on?
The site of infection and the presence of any underlying disease.
136
What are the common clinical presentations of African histoplasmosis in AIDS patients?
Common presentations include:
- Small papules resembling **molluscum contagiosum**
- Cold abscesses
- Draining sinuses
- Ulcers
137
What is the significance of Histoplasma serology in African histoplasmosis?
Histoplasma serology is often **NEGATIVE** in African histoplasmosis, which can complicate diagnosis.
138
What are the treatment options for disseminated or localized forms of African histoplasmosis?
Treatment options include:
1. **Itraconazole** (200 to 400 mg daily) - highly effective for long-term suppression in AIDS patients.
139
What is highly effective for long-term suppression in AIDS patients?
IV Amphotericin B (up to 1 mg/kg daily) is used for widespread and severe infections.
140
What are some effective treatments for certain cases of infections?
Posaconazole and Voriconazole.
141
What are the common sites of infection for North American blastomycosis?
Common sites of infection include:
- **Lungs**
- **Skin**
- **Bones**
- **CNS** (Central Nervous System)
142
What are the clinical features of pulmonary blastomycosis?
Clinical features include:
- Similar presentation to **pulmonary tuberculosis**
- May be **asymptomatic** or present with low-grade fever, chest pain, cough, and hemoptysis.
- Often coexists with disseminated disease.
143
How can blastomycosis be diagnosed?
Diagnosis can be made through:
- Finding the fungus in **KOH mounts** of pus, skin scrapings, or sputum as thick-walled, rounded, refractile, spherical cells with broad-based buds.
- Culture showing growth as a mycelial fungus at room temperature and producing characteristic yeast forms at higher temperatures.
144
What are the differential diagnoses for chronic skin granulomas?
Chronic skin granulomas must be differentiated from:
- **Tuberculosis**
- Other deep mycoses
- Nonmelanoma skin cancers
- Pyoderma gangrenosum
- Drug reactions caused by bromides and iodides.
145
What are the primary management options for coccidioidomycosis?
- **Itraconazole**: 200 to 400 mg daily, used in less severe forms or localized spread.
- **Voriconazole**: another treatment option.
- **Amphotericin B**: up to 1 mg/kg daily for widespread disseminated forms.
- Treatment is given for at least 6 months.
146
What is the duration of treatment for coccidioidomycosis?
Treatment is given for at least 6 months, and follow-up surveillance is necessary due to the risk of relapse, especially in immunosuppressed patients.
147
What are the clinical features of primary pulmonary coccidioidomycosis?
Presentation: chest infection, fever, cough, chest pain.
148
What are the complications associated with primary pulmonary coccidioidomycosis?
Complications: pleural effusion.
149
What is erythema multiforme or erythema nodosum in the context of coccidioidomycosis?
Occurs in 10%-15% of patients, more common in females, often with arthralgia or anterior uveitis.
150
What skin manifestations can occur in coccidioidomycosis?
Sometimes an early, generalized, macular and erythematous rash is seen.
151
What is the epidemiology of Coccidioides immitis and Coccidioides posadasii?
C. immitis is endemic in semidesert areas of South and Southwest United States.
152
Where is Coccidioides posadasii found?
Found in Arizona, New Mexico, Texas, and parts of Mexico and Central/South America.
153
What are the characteristics of endemic areas for coccidioidomycosis?
Endemic areas have high summer temperatures and low rainfall, characterized by cacti and mesquite bushes.
154
What is the exposure incidence in endemic areas?
Exposure incidence in endemic areas may be as high as 95%, with infection possible from soil, dust storms, or brief visits to endemic areas.
155
What are the diagnostic methods for coccidioidomycosis?
Characteristic ability: Coccidioides forms large spore-containing spherules (up to 250 µm).
156
What are the culture characteristics of Coccidioides?
Colonies are mycelial, fast growing, white, and cottony.
157
What does microscopy reveal in coccidioidomycosis?
Shows chains of arthrospores on older mycelium.
158
What is the role of serologic tests in coccidioidomycosis?
Valuable for diagnosis and prognosis; precipitin tests develop in 90% of infected individuals in 2 to 6 weeks but are short-lived.
159
What are the complications associated with disseminated coccidioidomycosis?
Lesions may develop in skin, subcutaneous tissues.
160
What is coccidioidomycosis?
Coccidioidomycosis may develop in skin, subcutaneous tissues, bones, joints, and all organs.
161
What is the presentation of coccidioidomycosis?
Presentation includes papules, nodules, abscesses, granulomas, ulcers, or discharging sinuses.
162
What is a complication of coccidioidomycosis?
Meningitis, which is usually not associated with signs of infection in other sites.
163
What complications can occur in AIDS patients with coccidioidomycosis?
Complications include persistent pneumonia, skin lesions, and widespread dissemination.
164
What is the likely diagnosis for a patient with erythema nodosum and arthralgia after visiting a desert region?
The likely diagnosis is coccidioidomycosis.
## Footnote
The causative organism is Coccidioides immitis or Coccidioides posadasii.
165
What is the likely fungal infection for a patient with chronic cough, fever, and cavitation on chest X-ray?
The likely fungal infection is Chronic Pulmonary Coccidioidomycosis.
## Footnote
Treatment includes Amphotericin B or Itraconazole.
166
What is the treatment for coccidioidomycosis similar to?
Histoplasmosis.
167
What are the two species that cause coccidioidomycosis?
Coccidioides immitis and Coccidioides posadasii.
168
What characterizes the primary pulmonary form of coccidioidomycosis?
Chest infection, fever, cough, and chest pain.
169
What is the average duration for treatment of coccidioidomycosis?
At least 6 months.
170
What is a common complication of disseminated coccidioidomycosis?
Meningitis.
171
What is the route of infection for coccidioidomycosis?
Respiratory, with rare direct implantation into the skin.
172
What is the significance of skin tests with coccidioidin?
They are of little value in diagnosing coccidioidomycosis.
173
What is the characteristic ability of Coccidioides species?
To form spore-containing spherules.
174
What does the clinical course of coccidioidomycosis depend on?
The site of infection and the presence of any underlying disease.
175
What is the management for primary pulmonary infection in coccidioidomycosis?
No specific therapy apart from rest is necessary.
176
What are the primary management strategies for disseminated coccidioidomycosis?
The primary management strategies for disseminated coccidioidomycosis include:
1. **Amphotericin B**: 1 mg/kg daily for severe cases.
2. **Itraconazole**: 200 to 400 mg daily for less severe forms.
3. **Fluconazole**: 200 to 600 mg daily as an alternative.
4. **Voriconazole**: used in specific cases.
5. **Follow-up surveillance**: necessary due to the risk of relapse.
177
How does the clinical presentation of primary pulmonary coccidioidomycosis differ from chronic pulmonary coccidioidomycosis?
The clinical presentation differs as follows:
| Feature | Primary Pulmonary Coccidioidomycosis | Chronic Pulmonary Coccidioidomycosis |
|---------|--------------------------------------|------------------------------------|
| Symptoms | Chest infection, fever, cough, chest pain | Chronic cough resembling tuberculosis |
| Complications | Pleural effusion, erythema multiforme | Skin lesions do NOT occur |
| Onset | Occurs within 3rd to 7th week | Persistent symptoms over time |
178
What is the significance of skin tests with coccidioidin in diagnosing coccidioidomycosis?
Skin tests are used to aid in the diagnosis of coccidioidomycosis.
179
What is the value of skin tests with coccidioidin in diagnosing coccidioidomycosis?
Skin tests with coccidioidin are of little value in diagnosing coccidioidomycosis because:
- They do not provide reliable results for active infections.
- Sensitization may not be detected effectively, especially in severe infections where cutaneous anergy is common.
180
What are the potential complications associated with disseminated coccidioidomycosis in AIDS patients?
In AIDS patients, disseminated coccidioidomycosis can lead to several complications, including:
- **Persistent pneumonia**: Ongoing respiratory issues.
- **Skin lesions**: Various forms including papules, nodules, and ulcers.
- **Widespread dissemination**: Involvement of multiple organ systems, including bones and joints.
- **Meningitis**: Although usually not associated with signs of infection in other sites, it can occur.
181
What factors influence the epidemiology of Coccidioides immitis and Coccidioides posadasii infections?
The epidemiology of Coccidioides immitis and Coccidioides posadasii infections is influenced by several factors:
- **Geographic location**: Endemic in semidesert areas of the southwestern United States and parts of Central and South America.
- **Environmental conditions**: High summer temperatures and low rainfall.
- **Exposure risk**: Skin tests indicate that exposure in endemic areas may be as high as 95%.
- **Local weather**: Dust storms can increase infection rates.
- **Demographics**: Certain ethnic backgrounds (e.g., African Americans, Filipinos, Mexicans) are more affected.
182
What is Paracoccidioidomycosis?
Paracoccidioidomycosis is caused by the dimorphic fungus **Paracoccidioides brasiliensis**. It primarily affects the respiratory tract and can disseminate to mucous membranes and lymph nodes.
183
What are the primary clinical features of Paracoccidioidomycosis?
Key clinical features include:
- **Pulmonary form**: Acute infections are rare, while chronic infections are more common, presenting with weight loss and chronic cough.
- **Mucocutaneous form**: Oral or circumoral lesions, which may be small granulomas or ulcers that heal with scarring.
- **Lymphatic form**: Involvement of lymph nodes, which may be enlarged and tender.
184
What are the diagnostic methods for Paracoccidioidomycosis?
Diagnosis can be made using the following methods:
1. **KOH preparation**: Sputum, exudates, and scrapings show round yeasts with characteristic multiple budding.
2. **Culture**: The organism exhibits a cottony mycelial phase at room temperature and a characteristic yeast phase on enriched media at 37°C.
3. **Serology**: Immunodiffusion assay and complement-fixation tests can confirm the diagnosis, with antibodies to **pb27** and **87-kDa** antigens being highly specific.
185
What is the management approach for Paracoccidioidomycosis?
Management includes:
- **Itraconazole**: Treatment of choice, producing remissions in 3 to 6 months.
- **Voriconazole**: Produces similar responses as itraconazole.
- **IV Amphotericin B**: Used for very extensive infections and in severely ill patients, especially those with progressive disseminated disease.
186
What is the risk for patients with progressive disseminated disease?
Patients should be reviewed periodically due to the risk of relapses, and severe pulmonary or intraoral fibrosis may remain after treatment.
187
Where are Talaromyces marneffei infections primarily found?
Talaromyces marneffei infections are primarily found in Southeast Asia, particularly in Thailand, South China, and Vietnam.
188
What are the key epidemiological characteristics of Talaromyces marneffei infections?
Key epidemiological characteristics include natural infections occurring in bamboo rats of the genus **Cannomys** and being most common after the rainy season.
189
Who is affected by Talaromyces marneffei infections?
It affects both healthy individuals and those with immune defects, particularly **AIDS** patients and those receiving **Rituximab** therapy.
190
What are the clinical features of Talaromyces marneffei infections?
Clinical features include:
- **Localized pulmonary disease**: Symptoms resemble chronic pulmonary disease.
- **Disseminated disease**: More than 50% of AIDS patients with this infection present with multiple skin lesions, which are umbilicated papules that may enlarge and ulcerate, often scattered on the face and trunk.
- Involvement of internal organs such as the liver, GI tract, spleen, and bone marrow may occur.
191
What is the likely diagnosis for a patient with chronic pulmonary infection and oral lesions?
The likely diagnosis is Paracoccidioidomycosis. The treatment of choice is Itraconazole (200-400 mg daily).
192
What is Paracoccidioides brasiliensis and what disease does it cause?
A dimorphic fungus that causes a respiratory tract infection with a tendency to disseminate to mucous membranes and lymph nodes.
193
What are the common geographical locations where Paracoccidioidomycosis is reported?
Brazil, Colombia, Argentina, and Mexico.
194
What is the typical clinical presentation of chronic pulmonary infection caused by Paracoccidioidomycosis?
It is usually slowly progressive with weight loss and chronic cough.
195
What diagnostic methods can be used to confirm Paracoccidioidomycosis?
Sputum, exudates, and scrapings can be screened using KOH, and serology can confirm the diagnosis.
196
What is the treatment of choice for Paracoccidioidomycosis?
Itraconazole is the treatment of choice, producing remissions in 3 to 6 months.
197
What is Talaromyces marneffei and where is it commonly found?
A fungus that was thought to be a member of the genus Penicillium, commonly found in Southeast Asia.
198
What are the clinical features of Talaromyces marneffei infection in AIDS patients?
Localized pulmonary or disseminated disease with multiple skin lesions that may enlarge and ulcerate.
199
How is Talaromyces marneffei transmitted?
It is inhaled via the lungs.
200
What is the significance of the rainy season in relation to Talaromyces marneffei infections?
Infections are most common after the rainy season.
201
What is the role of immune defects in Talaromyces marneffei infections?
It affects otherwise healthy individuals as well as those with immune defects, particularly AIDS patients.
202
What are the clinical features of Paracoccidioidomycosis and how do they vary based on the site of infection?
The clinical features of Paracoccidioidomycosis depend on the predominant site of infection:
- **Pulmonary form**: Acute infections are rare and may subside while disseminate.
203
What are acute infections?
Acute infections are rare and may subside while dissemination occurs.
204
What are chronic infections?
Chronic infections are more common, presenting as slowly progressive with weight loss and chronic cough.
205
How may lesions present in chronic infections?
Lesions may be bilateral and nodular, with CXR showing extensive fibrosis.
206
What is the mucocutaneous form?
Oral or circumoral lesions are common, as well as lesions in the nose, conjunctivae, and anus. These may present as small granulomas or ulcers that heal with scarring, potentially causing deformity.
207
What is the lymphatic form?
Cervical lymph nodes may be enlarged, tender, and tethered to the overlying skin, but rarely suppurate.
208
What are other sites of involvement in infections?
Other sites can include the spleen, intestines, lungs, and liver, with this infection being uncommon in AIDS patients.
209
What is the management approach for severe Paracoccidioidomycosis?
The management of severe Paracoccidioidomycosis includes:
210
What is itraconazole?
Itraconazole is the treatment of choice, typically producing remissions in 3 to 6 months.
211
What is voriconazole?
Voriconazole produces similar responses as itraconazole.
212
What is IV Amphotericin B?
IV Amphotericin B is recommended for very extensive infections and in severely ill patients, particularly those with the progressive disseminated type.
213
What is the follow-up for patients?
Due to the risk of relapses, patients should be reviewed periodically after primary therapy. Severe pulmonary or intraoral fibrosis may remain after treatment.
214
What are the epidemiological factors associated with Talaromyces marneffei infections?
Talaromyces marneffei infections are primarily associated with the following epidemiological factors:
215
Where is Talaromyces marneffei confined to?
Confined to Southeast Asia, particularly Thailand, South China, and Vietnam.
216
Which regions have reported cases of T. marneffei infections?
Particularly Thailand, South China, and Vietnam, with reports in Northeast India and cases imported to Europe and the United States.
217
What is the natural source of T. marneffei?
The natural source of T. marneffei is unknown, but infections occur in **bamboo rats** of the genus Cannomys, which are large burrowing rodents.
218
When are T. marneffei infections most common?
Most common after the **rainy season**.
219
Who is particularly susceptible to T. marneffei infections?
Individuals with **immune defects**, including those with AIDS and patients receiving Rituximab biological therapy.
220
What are the clinical features of T. marneffei infections in AIDS patients?
In AIDS patients, T. marneffei infections typically present with:
- **Localized pulmonary or disseminated disease**: Symptoms may resemble chronic pulmonary disease.
- **Skin lesions**: More than 50% of AIDS patients with this infection develop multiple skin lesions, which are umbilicated papules that may enlarge and ulcerate, often scattered on the face and trunk.
- **Potential involvement of internal organs**: The liver, GI tract, spleen, and bone marrow may also be affected, indicating a systemic nature of the infection.
221
What are the characteristic features of T. marneffei in diagnosis?
T. marneffei forms characteristic yeast-like cells divided by a septum, best seen with methenamine silver. The cells are small (2 to 4 µm in diameter) and may be highlighted with leishman stain. The culture shows a green or grayish mold that produces typical conidiophores and a diffusible red pigment. PCR is used for identification of cultures.
222
What is the main portal of entry for Cryptococcus neoformans and its clinical presentation?
The main portal of entry for Cryptococcus neoformans is inhalation.
223
What is the portal of entry for Cryptococcus neoformans?
Inhalation into the lungs.
224
What are the common clinical features of cryptococcosis in AIDS patients?
Classic signs of meningitis, including changes in consciousness, mental changes, and nerve palsies. Pulmonary infection is found in 10% of those with meningitis, and cutaneous lesions may develop in 10% of cases, often presenting as acneiform papules or pustules.
225
What diagnostic methods are used for identifying Cryptococcus species?
Direct microscopy of India ink or Nigrosin mounts reveals large (5 to 15 µm in diameter) budding cells with capsules. Serologic tests are rapid and specific, with the main test being an antigen-detection assay using latex agglutination or enzyme-linked immunosorbent assay.
226
What is the management approach for cryptococcosis in non-AIDS patients?
Typically involves IV Amphotericin B combined with flucytosine, which is the most frequently used drug regimen. For single skin lesions with no other signs of infection, fluconazole or itraconazole may be used.
227
What is the likely infection and causative organism for a patient from an endemic area who develops multiple umbilicated papules on the face and trunk?
The likely infection is Talaromyces marneffei (Penicilliosis). The causative organism is T. marneffei.
228
What is the likely diagnosis for a patient presenting with a solitary nodule that ulcerates after trauma?
The likely diagnosis is a cutaneous fungal infection.
229
What is the likely diagnosis for a solitary nodule that ulcerates after trauma?
The likely diagnosis is Primary Cutaneous Cryptococcosis caused by Cryptococcus neoformans.
230
What are the characteristic cells formed by T. marneffei?
Yeast-like cells divided by a septum.
231
What is the main portal of entry for Cryptococcus neoformans?
Inhalation into the lungs.
232
What are the common clinical manifestations of cryptococcosis in AIDS patients?
Meningitis and cutaneous lesions.
233
What is the significance of serotype D in cryptococcosis?
It is more likely to be found in skin lesions, occurring in 10% to 15% of cases of disseminated cryptococcosis.
234
What is the most frequently used drug regimen for non-AIDS patients with cryptococcosis?
IV Amphotericin B combined with flucytosine.
235
What is a common diagnostic method for identifying Cryptococcus?
Direct microscopy using India ink or Nigrosin mounts.
236
What is a characteristic feature of cryptococcal cells?
They are large (5 to 15 µm in diameter) and have capsules.
237
What is the role of antigen-detection assays in diagnosing cryptococcosis?
They are simple and rapid tests performed on blood or cerebrospinal fluid.
238
What is the clinical significance of cutaneous lesions in cryptococcosis?
They may indicate dissemination of the infection.
239
What is the recommended management for AIDS patients with cryptococcosis?
A 10- to 14-day course of Amphotericin B with or without flucytosine, followed by long-term fluconazole.
240
What are the characteristic features of Cryptococcus neoformans and how does it present in patients with HIV infection?
Cryptococcus neoformans is characterized by encapsulation.
241
What is Cryptococcus neoformans?
Cryptococcus neoformans is characterized by encapsulated yeasts that are large (5 to 15 µm in diameter) and can be observed using India ink or Nigrosin mounts.
242
What are the symptoms of Cryptococcus neoformans in HIV-infected patients?
In HIV-infected patients, it often presents with signs of meningitis, including changes in consciousness and mental changes.
243
What cutaneous lesions may develop from Cryptococcus neoformans?
Cutaneous lesions may develop as a result of dissemination or direct inoculation, often appearing as solitary nodules that can ulcerate and lead to local lymphadenopathy.
244
What is the significance of antigen detection tests in diagnosing cryptococcosis in AIDS patients?
Antigen detection tests are crucial in diagnosing cryptococcosis, especially in AIDS patients, as they are rapid and specific. High titers of cryptococcal antigen are typically found in the serum and cerebrospinal fluid of AIDS patients, aiding in the diagnosis of disseminated disease.
245
How does the management of cryptococcosis differ between AIDS and non-AIDS patients?
In non-AIDS patients, management typically involves IV Amphotericin B combined with flucytosine, which is the most frequently used regimen. For single skin lesions without other signs of infection, fluconazole or itraconazole may be used. In contrast, AIDS patients often experience very high relapse rates and require a 10- to 14-day course of Amphotericin B, followed by long-term fluconazole therapy.
246
What are the differential diagnoses to consider for cryptococcosis?
Differential diagnoses to consider include other fungal infections, bacterial infections, and neoplastic processes.
247
What are the differential diagnoses to consider when evaluating a patient with suspected cryptococcosis?
It is important to consider other disseminated mycoses such as histoplasmosis and other systemic mycoses that can mimic cryptococcosis in AIDS patients.
248
What are the clinical features of cryptococcosis in patients with HIV?
Cryptococcosis may present with classic signs of meningitis, such as fever, headache, and altered mental status, along with cutaneous lesions that may be more widespread and symptomatic.
249
How do the clinical features of cryptococcosis in HIV patients differ from those in healthy individuals?
Healthy individuals may exhibit solitary lesions that are the only clinical manifestation, and they may not show the systemic signs associated with disseminated disease.
250
What are the common skin lesions associated with systemic candidiasis in neutropenic patients and IV drug abusers?
In neutropenic patients, skin lesions may present as widespread skin nodules and muscle pains. In IV drug abusers, they may present with a follicular, pustular rash in the beard area and scalp.
251
What is the management approach for systemic candidiasis caused by non-albicans Candida species?
Management includes avoiding antifungal agents like fluconazole and ketoconazole due to resistance. Treatment options include IV amphotericin B (conventional or lipid formulations).
252
What are the treatment options for mucormycosis?
Treatment options include IV amphotericin B (conventional or lipid-associated), caspofungin, or fluconazole, depending on the specific species.
253
What are the characteristics and risk factors associated with mucormycosis?
Mucormycosis is a rare disease caused by Mucoromycetes fungi, affecting patients with poorly controlled diabetes, neutropenia, or renal disease. It can result from direct invasion following trauma or can invade necrotic burned areas.
254
What are the common fungi associated with other opportunistic mycoses that can produce skin lesions?
Common fungi include Aspergillus, Scedosporium, Trichosporon, and Fusarium. Skin infections are primarily seen in severely immunocompromised patients, with Aspergillus causing large necrotic lesions and Fusarium causing target-like lesions.
255
What challenges are faced in the diagnosis of systemic mycosis?
Diagnosis is challenging due to the presence of organisms as commensals in human sites, compromised capacity to produce diagnostic antibody titers in severely ill patients, and the difficulty in interpreting laboratory data related to the clinical state of the patient.
256
A patient with poorly controlled diabetes presents with necrotic lesions on the face and a history of trauma. What is the likely fungal infection, and what is the treatment?
The likely fungal infection is mucormycosis. Treatment includes IV Amphotericin B, with lipid-associated formulations showing encouraging results.
257
A patient presents with large necrotic lesions resembling ecthyma gangrenosum. What is the likely fungal infection, and what diagnostic test can confirm it?
The likely fungal infection is Aspergillosis. Laboratory detection of Galactomannan can confirm it.
258
What is Aspergillosis?
A fungal infection caused by Aspergillus species.
259
How can laboratory detection of Galactomannan confirm the diagnosis?
It is used to diagnose Aspergillosis.
260
What is the likely diagnosis for a patient with a pustular rash in the beard area and scalp after IV drug use?
The likely diagnosis is Systemic Candidiasis.
261
What is the treatment for Systemic Candidiasis?
Treatment includes IV Amphotericin B, Caspofungin, or Fluconazole.
262
What is the diagnosis for a patient with a chronic, painless nodule on the chest wall with yellow sulfur granules?
The diagnosis is Actinomycosis caused by filamentous bacteria.
263
What is the diagnosis for a patient with a chronic, painless nodule on the chest wall with draining sinuses?
The diagnosis is Actinomycosis caused by filamentous bacteria.
264
What is the diagnosis for a patient with a chronic, painless nodule on the chest wall with draining sinuses and sulfur granules?
The diagnosis is Actinomycosis caused by filamentous bacteria.
265
What is the diagnosis for a patient presenting with a chronic, painless nodule on the chest wall with draining sinuses and sulfur granules?
The diagnosis is Actinomycosis caused by filamentous bacteria.
266
What are the common skin lesions associated with systemic candidiasis in neutropenic patients?
Widespread skin nodules and muscle pains.
267
What is the management for non-albicans Candida species?
Avoid antifungal agents like Fluconazole and Ketoconazole due to resistance.
268
What are the common causes of mucormycosis?
Mucor, Lichtheimia, and Rhizopus fungi.
269
What conditions can lead to mucormycosis?
Poorly controlled diabetes, neutropenia, or renal disease.
270
What is a significant risk factor for developing actinomycosis?
Infection following trauma or natural disasters.
271
What is the treatment for infections caused by Fusarium?
Amphotericin B is used, with Voriconazole increasingly for Aspergillosis.
272
Why is laboratory confirmation of systemic mycosis difficult?
Many organisms are commensals in human sites, complicating diagnostic antibody production.
273
What is the role of PCR-based molecular assays in diagnosing systemic mycosis?
They are helpful in some cases for diagnosis.
274
What type of lesions can Aspergillus cause in immunocompromised patients?
Large necrotic lesions such as ecthyma gangrenosum and smaller papules.
275
What is a common complication of mucormycosis related to blood vessels?
Widespread infarction due to invasion of blood vessels.
276
What is the management approach for systemic candidiasis caused by non-albicans Candida species?
Management includes avoiding antifungal agents like fluconazole and ketoconazole due to resistance. Treatment options include IV amphotericin B (conventional or lipid-associated), caspofungin, or fluconazole, with a focus on species-specific therapy.
