Fungi + Sketchy PDF

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Superficial Fungal Infections Malassezia furfur – Malassezia’s Italian Restaurant  Disease includes pityriasis versicolor (hypo- and hyperpigmented patches on skin)  Treatment via topical selenium sulfide (or imidazoles)  Other comments o Spaghetti and meatball appearance with KOH prep o Thrives under heat and humid conditions, e.g. sunlight exposure o Fungus is localized to the stratum corneum o Neonates that receive total parenteral nutrition (lipid-based transfusion) are susceptible to sepsis and thrombocytopenia Exophiala werneckii  Disease includes dark to brown painless patches on the soles of hands and feet  Treatment via topical selenium sulfide (or imidazoles) Cutaneous Fungal Infections (on skin, hair, and nails) Dermatophytes (Trichophyton, Epidermophyton, and Microsporum) – Tinea Tin Man  Disease includes tinea infections o Tinea capitis o Tinea corporis – “ring worm” o Tinea cruris – “jock itch” o Tinea pedis – “athlete’s foot” o Tinea unguium – onychomycosis  Treatment via topical imidazole; more serious infections via griseofulvin (has lots of associated GI side effects)  Other comments o Hyphae present with KOH prep or direct examination of Microsporum via Wood’s Light o Thrives under hot and humid conditions; athletes are commonly affected, but transmission also occurs via pets o Fungi functions to secrete keratinase, which digests the keratin resulting in scaling of skin, hair loss, and crumbling of nails Subcutaneous Fungal Infections Sporothrix schenckii – Shanked by a Rose  Disease includes ulcerations, nodules, and ascending lymphadenitis – “Rose Gardener’s Disease”  Treatment via itraconazole or saturated potassium iodide (outdated)  Other comments o (Dimorphic fungi) Hyphae present with KOH prep in the cold or cigar-shaped budding yeast at 37ºC Chromoblastomycosis  Disease includes small violet wart-like lesions that cluster like cauliflowers  Treatment via itraconazole and local excision  Other comments o Copper-colored sclerotic bodies with KOH prep; saprophytes are commonly found in rotting wood Systemic Fungal Infections Histoplasma capsulatum – The Historian’s Cave  Disease includes pneumonia (cavitary lesions similar to TB), erythema nodosum (common to legs), and hepatosplenomegaly in immunocompromised patients  Transmission via respiratory droplets – common in bird and bat droppings (cave) and the Mississippi, Missouri, and Ohio River Valley  Treatment via -azole drugs; systemic infections via amphotericin B  Other comments o (Dimorphic fungi) Macrophages will small intracellular oval bodies on histological slide and is smaller than RBCs; serum and urine rapid antigen test Blastomyces dermatitis – The Blast of the Cannons  Disease includes pneumonia (patchy alveolar infiltrate on CXR or cavitary lesions) and osteomyelitis (skin and bone) in immunocompromised patients  Transmission via respiratory droplets – common to the Great Lakes and Ohio River Valley (more than Histoplasma capsulatum)  Treatment via -azoles; systemic infections via amphotericin B  Other comments o (Dimorphic fungi) Broad-based budding on histological slide and is the same size of RBCs; urine rapid antigen test Coccidiodes immitis – Presidio San Joaquin  Disease includes San Joaquin Valley Fever characterized by pneumonia (cavitary lesions), arthralgia, erythema nodosum, and meningitis in immunocompromised patients

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Transmission via respiratory droplets – common in dust and earthquakes, e.g. California and S.W. United States and N. Mexico Treatment via -azole drugs; systemic infections via amphotericin B Other comments o (Dimorphic fungi) “Mold in the cold, spherule endospore in the heat”, much larger than RBCs

Cryptococcus neoformans & gatti – Crypt for Cryptococcus  Disease includes pulmonary symptoms, meningitis, fever, skin ulcers, and bone lesions  Transmission via respiratory droplets – common in pigeon droppings  Treatment via joint therapy of amphotericin B, flucytosine, and fluconazole for maintenance  Other comments o Fungi is heavy encapsulated (and urease positive) and therefore can be visualized with an India Ink stain, which shows wide encapsulated halo o Latex agglutination test can be used to detect the polysaccharide antigen, which induces agglutination o Bronchopulmonary washings of lung tissue resemble “soap bubble” lesions in the brain Candida albicans – Candid Canadians  Disease includes oral thrush (pseudomembranes with white exudate), vaginitis, diaper rash, esophagitis, and disseminated  Transmission via direct contact – common in immunocompromised patients, steroid users, diabetics, women on birth control, and patients using excessive antibiotics  Treatment via nystatin, fluconazole, and amphotericin B  Other comments o (Dimorphic fungi) “Yeast in the cold and mold in the heat”; catalase positive thus chronic granulomatous disease patients are highly susceptible to fungal infection o Present in normal GI tract and oral cavity, thus is common contaminant in sputum but NOT blood cultures o This is an AIDS defining illness when CD4+ count...