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Reference Material

Tips and Mnemonics:

• Histoplasma: Histo Hides (within macrophages). Smaller than red blood cells.
• Blastomyces: Blasto is Big and Broad-based (budding). Same size as red blood cells.
• Coccidioides: Coccidio is a Cocktail of endospores (inside a spherule). Much larger than red blood cells.
• Paracoccidioides: Paracoccidio Pirate ship (Captain's wheel appearance).
• Sporothrix: Think of a rose gardener (rose gardener's disease) with a cigar (cigar-shaped yeast).

Click on any diagram to zoom in:

Fungal species	Epidemiology	Clinical presentation	Laboratory diagnosis
Sporothrix schenckii	Associated with gardening; often transmitted via a thorn prick.	Pustules, ulcers, and subcutaneous nodules along the lymphatics.	Culture (25ºC): branching hyphae. Biopsy: round or cigar-shaped budding yeasts.
Coccidioides immitis	Southwestern states (desert areas). Mold form is present in soil.	Pulmonary form: flu-like illness, cough, erythema nodosum. Disseminated form: affects skin, bones, and lungs.	Culture (25ºC): forms hyphae. Biopsy: at 37ºC forms thick-walled spherules filled with endospores.
Histoplasma capsulatum	Ohio and Mississippi River valleys. Soil, bird and bat droppings (chicken coops, caves).	Pulmonary: similar to tuberculosis (lung granulomas with calcifications). Disseminated: lungs, spleen, liver	Culture (25ºC): branching hyphae. Biopsy: oval yeast cells within macrophages.
Blastomyces dermatitidis	Ohio and Mississippi River valleys, Great Lakes region. Found in soil.	Pulmonary: pneumonia. Disseminated form is common and severe.	Culture (25ºC): branching hyphae. Biopsy: large, round yeasts with doubly refractile wall and single broad-based bud.
Paracoccidioides brasiliensis	Central and South America	Mucocutaneous: chronic mucocutaneous or cutaneous ulcers, can progress to lymph nodes and lungs	Culture (25ºC): multiple blastoconidia. Biopsy: cells covered in budding blastoconidia