Fungal Infections Flashcards
A patient is experiencing an exacerbation of her asthma. Her lungs display infiltrates and eosinophilia. Later that day, a 45-year-old man presents with fever, productive cough, and rust-colored sputum. The patient was diagnosed with TB 20 years ago. A chest Xray shows cavitary lesions, and a biopsy reveals necrotizing inflammation, vascular thrombi, and branching fungal hyphae. What pathogen do these patients have?
Aspergiilus species (Fungus) -Allergic bronchopulmonary aspergillosis complicates asthma -Aspergilloma (fungus ball) occurs in persons with pulmonary cavities -Invasive aspergillosis afflicts neutropenic patients
A 24-year old woman with Type 1 diabetes presents to the ER in severe respiratory distress. Her history is significant for antibiotic-resistant sinusitis. The patient dies of respiratory failure, and autopsy shows a septic, embolic infarction of the lung. What pathogen is responsible?
Zygomycetes (Fungus) Mucormycosis -severe, invasive, necrotizing, opportunistic infection of lung/sinuses -severe diabetics are susceptible -fungal hyphae grow into arteries, causing rapidly progressive septic infarction
A 47-year-old chemotherapy patient complains of constitutional symptoms and dyspnea. A chest X-ray shows pulmonary infiltrates and thin-walled cavities. A mucicarmine stain of a lung biopsy discloses budding yeast surrounded by a mucin–rich capsule. If left untreated, her disease will spread to the CNS and cause a fatal meningitis. What pathogen is responsible?
Cryptococcus neoformans (Fungus) Cryptococcosis -proteoglycan or “mucinous” capsule is key finding -almost exclusively affects persons with impaired cell-mediated immunity -lung is site of entry, but over 95% of cryptococcal infections involve the meninges and brain
What type of fungi cause ringworm, athlete’s foot, and other localized, superficial infections of keratinized tissues?
Dermatophytes
A patient presents with fever, non-productive cough, and progressive dyspnea. She has a diffuse, progressive pulmonary process on X-ray. Microscopically, her alveoli contain a frothy eosinophilic material composed of macrophages and ruptured cysts of the pathogen. What is the name of this pathogen, which happens to be the most common opportunistic pathogen in persons with AIDS?
Pneumocystis jiroveci (Fungus) Pneumocystis Jiroveci Pneumonia -progressive shortness of breath with non-productive cough -diagnosis requires recovery of the alveolar material, which shows the cysts -diffuse and progressive pulmonary process -most common opportunistic pathogen in persons with AIDS
This chronic skin infection is common in barefooted agricultural workers in the tropics. Histologically, the fungi are brown and round – “copper pennies.”
Chromomycosis -“copper pennies”
A 35-year-old man presents with fever, headache, and cough. Pathological findings include necrotizing granulomas in the lung, lymph nodes, spleen, and liver. His systemic granulomatous condition sounds like TB, but then he tells you that he’s an avid spelunker with a fondness for bats. What pathogen just went up on your differential?
Histoplasma capsulatum (Fungus) Histoplasmosis -systemic granulomatous disease -inhalation of infectious spores from feces of birds or bats -starts in lung, disseminates to monocyte/macrophage system -granulomas will calcify and are called “fibrocaseous nodules”
A 27-year-old woman from the southwestern US presents with a flu-like syndrome. There are necrotizing, caseous granulomas visible in her lungs. Fortunately, since she is not Filipino or immunocompromised, her disease is acute and self-limited. What pathogen might be responsible for this disease that clinically and pathologically resembles TB?
Coccidioides immitis (Fungus)) Coccidiomycosis -necrotizing, caseuous granulomas -inhalation of spores from soil -southwestern USA (San Joaquin Valley - “valley fever”) -Filipinos and immunocompromised persons are susceptible to disseminated disease
A 31-year-old man with AIDS complains of painful swallowing. He has a whitish membrane covering much of his tongue, palate, and esophageal mucosa. In the room next door, a pregnant woman (who is taking antibiotics) has a white vaginal discharge with vaginal and vulvar itching. What pathogen do they have?
Candida albicans (Fungus) -endogenous flora, resides in oropharynx, GI tract, vagina -a common opportunistic pathogen
This disease is a slowly progressive, localized, and often disfiguring infection of skin, soft tissues, and bone. It is most common in the tropics among farmers and other outdoor laborers, and the foot is the most common site. The inflammation fails to clear the pathogen, which is why the swelling does not subside and becomes disfiguring. The interconnected lesions produce laterally-running sinus tracts.
Mycetoma -tropics -farmers, outdoor laborers -“Madura foot” -multiple abscesses interconnected by lateral sinus tracts
A gardener comes into the clinic with a skin problem. She says it started as a single lesion on her hand, but more lesions developed in the next few weeks. You notice that this chain of nodules follows a lymphatic drainage channel, and they drain a serosanguineous fluid. What pathogen are you thinking?
Sporothrix schenckii (Fungus) Sporotrichosis -chain of nodular skin lesions; the periphery is granulomatous, the center is suppurative -nodules appear along lymphatic drainage of primary lesion -common in gardeners, botanical nursery workers
A patient presents with a flu-like illness. The lungs show small, focused areas of consolidation in the upper lobes, and are infected with spherical yeasts with broad-based buds and multiple nuclei in a central body. Later on, the patient develops skin lesions that resemble squamous cell carcinomas. What pathogen is likely responsible?
Blastomyces dermatitidis Blastomycosis -granulomatous pulmonary disease; usually produces a focal bronchopneumonia with upper lobe infiltrates -skin is the most common site of dissemination -spherical yeasts with broad-based buds and multiple nuclei in a central body
A 50-year-old male immigrant from Brazil presents with a flu-like illness. The lungs show small, focused areas of consolidation in the upper lobes, and are infected with spherical yeasts with broad-based buds and multiple nuclei in a central body. Later on, the patient develops skin lesions that resemble squamous cell carcinomas. What pathogen is likely responsible?
Paracoccidioides brasiliensis Paracoccidiomycosis “South American Blastomycosis” -granulomatous pulmmonary disease, similar to Blastomycosis -can be re-activation of latent infection in immigrants, especially males, from Central/South America
