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Flashcards in Fungal Infections Deck (29)
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1
Q

What causes tinea versicolor?

A

Superficial yeast infection caused by Pityrosporum ovale aka Malassezia furur. Organism oxidizes fatty acids in the skin and inhibits tyrosinase in the melanocytes leading to loss of pigmentation

2
Q

What is the clinical presentation of tinea versicolor?

A

Velvety tan, pink or white macules. Hypopigmented areas that do not tan with the rest of the skin. trunk, upper arms, neck and groin. Lesions may scale if scraped

3
Q

What are laboratory findings of tinea versicolor?

A

Skin scrapings seen on KOH prep show budding spores and large hyphae “spaghetti and meatballs”

4
Q

What are treatment options of tinea versicolor?

A

Selenium sulfide lotion 2.5% (Rx) apply once daily for 7 days. Apply with a cotton ball, allow to dry 15 min prior to bathing. To prevent recurrence maintenance therapy twice a month

5
Q

What are tinea infections?

A

located in the stratum corneum and caused by dermatophytes. dermtophytes digest keratin leading to scaling, nails thicken/crumble, hair loss.

6
Q

How is tinea diagnosed?

A

Microscopic evaluation-Skin margin scraping and KOH prep. Fungal culture-Takes 2 weeks

7
Q

What is the presentation and treatment of tinea corporis?

A

Ring shaped lesion with well-demarcated margins. Central clearing. Scaly, erythematous border. Treat with a topical azole antifungal (apply 1-2 x daily for 2-4 weeks)

8
Q

What is the presentation and treatment of tinea cruris?

A

located in groin, inguinal folds. Borders distinct. Lesions large, erythematous. Macular with central clearing. Hallmark: pruritus with burning. Treatment: topical azole antifungal

9
Q

What is the presentation and treatment of tinea pedis?

A

scaling, maceration, fissures b/w toes, diffuse scaling of the soles. vesicles and bullae on the sole of the foot, great toe and instep. Treatment: topical azole antifungal

10
Q

What is the presentation and treatment of tinea capitis?

A

Most cases in children. Inflamed scaly, alopecic patches. Tender, pustular nodules. Treatment: griseofulvin for 8 weeks

11
Q

What is the presentation and treatment of tinea unguium (onychomycosis)?

A

Typically toenails but can affect fingernails. Onycholysis (nail lifts up) may occur. Infection usually moves distal to proximal. Treat with oral itraconazole x 12 weeks or terbinafine if itraconazole fails

12
Q

What are the different locations of candidiasis?

A

Intertrigo-Axillae, under breasts, groin, intergluteal folds. Balantitis-Glans penis. Candidal folliculitis-Follicular pustules. Candidal paronychia-Nail folds. Thrush-Mouth and tongue. Diaper dermatitis

13
Q

What is the treatment of the different candidiasis infections?

A

Thrush-Nystatin, Clotrimazole. Cutaneous-powder (Nystatin), Clotrimazole (Lotrimin), ketoconazole. If failure of topical therapy then Oral fluconazole (diflucan)

14
Q

How do you diagnose and treat systemic candidiasis infections?

A

Blood cultures. May isolate organisms from urine or sputum. Isolated candida from blood cultures is considered a sign of serious disease. IV antifungal treatment such as fluconazole. Fundoscopic exam to excluded endopthalmitis

15
Q

What is the epidemiology of histoplasma capsulatum?

A

Found in the soil from bird or bat droppings. Endemic along major river valleys. Inhalation of the spores leads to lymphatogenous spread to other organs

16
Q

How is histoplasma capsulatum diagnosed?

A

Asymptomatic. Past infection may be noted by calcifications on routine xrays-Lungs,Spleen

17
Q

What is the epidemiology of coccidioidomycosis?

A

Infection occurs secondary to inhalation of molds from endemic areas. Southwestern US, Mexico, Central America, South America.

18
Q

What is the clinical presentation of coccidiodomycosis?

A

Pedal edema, Chest pain, Cough with blood tinged sputum, Fever, night sweats, Headache, Joint stiffness, Muscle pain, Anorexia, Erythema nodosum

19
Q

What happens in each body system if coccidiodomycosis disseminated?

A

Skin (erythema nodosum, verrucous skin lesions), Lungs (cavities, infiltrates, empyema, pleural effusion). Bones (lytic lesions). Soft tissues (abscesses). Lymph nodes (hilar and/or mediastinal lymphadenopathy, lymphadenitis and abscess formation). Meningitis

20
Q

What are characteristic lab results of coccididomycosis?

A

Leukocytosis, Eosinophilia, ELISA for IgM and IgG antibodies, Tissue or bone biopsy may reveal spores. Spinal fluid-Complement fixing antibodies, increased cell count, lymphocytosis, reduced glucose

21
Q

What is the treatment for coccidiomycosis?

A

Refer to ID specialist. Amphotericin B IV. Oral azoles. May require prolonged therapy. Surgical incision and drainage of abscess formation

22
Q

What is the epidemiology of cryptococcus?

A

caused by crytococcus neoformans. Yeast that is found in the soil and on dried pigeon poop. Most common cause of fungal meningitis. Rare in immunocompetent persons. 3 forms of infection: cutaneous, respiratory, meningeal

23
Q

What is the clinical presentation of crytococcus?

A

Pulmonary-Can lead to respiratory failure. CNS- HA, Confusion, Mental status changes, Cranial nerve abnormalities, Nausea, vomiting

24
Q

How is cryptococcus diagnosed?

A

Crytococcal antigen found in the infected organ and in the serum of AIDS patients. Respiratory- Sputum culture or pleural fluid. Lumbar puncture- Increased opening pressure, increased protein, decreased glucose. Positive India ink prep shows budding, encapsulated fungal cells.

25
Q

What is the treatment for cryptococcus?

A

Referral to ID specialist. Amphotericin B IV x 2 weeks. Followed by fluconazole x 8 weeks

26
Q

What is the epidemiology of aspergillosis?

A

caused by aspergillus fumigatus. Tissue invasion occurs with: Immunosuppression, Severe and prolonged neutropenia, High dose glucocorticoids

27
Q

What are clinical presentations of aspergillosis?

A

fever, chest pain, shortness of breath, cough, hemoptysis. CXR: single or multiple nodules with or without cavitation, patchy or segmental consolidation, peribronchial infiltrates.

28
Q

How is aspergillosis diagnosed?

A

high levels of IgE and IgG Aspergillus percipitins.
Galactomannan antigen from serum or bronchioalveolar lavage fluid. CT scan of the lungs-Ground glass infiltrates with a “halo sign” then development of a cavitary lesion

29
Q

What is allergic bronchopulmonary aspergillosis?

A

Preexisting asthma and worsening bronchospasm and pulmonary infiltrates. Waxing and waning course. May result in bronchiectasis and fibrotic lung disease. Treatment-Antifungals and steroids