Which of the following conditions is acquired by INHALATION of fungal spores?

Correct answer: A. Blastomycosis

• A. CORRECT. BLASTOMYCOSIS is a deep systemic mycosis caused by Blastomyces dermatitidis, acquired by INHALING conidia (spores) from moist soil and decaying wood, particularly in the Ohio and Mississippi river valleys. It begins as a pulmonary infection that may disseminate; oral lesions appear as chronic, non-healing ulcers with irregular indurated borders that closely mimic squamous cell carcinoma — biopsy showing broad-based budding yeast is diagnostic.
• B. LUDWIG ANGINA is a polymicrobial BACTERIAL cellulitis of the submandibular, sublingual and submental spaces, almost always odontogenic from a lower molar.
• C. CANDIDIASIS is an OPPORTUNISTIC overgrowth of commensal Candida already present in the mouth, triggered by antibiotics, steroids, xerostomia or immunosuppression. It is not acquired by inhaling spores.
• D. ACTINOMYCOSIS is caused by Actinomyces israelii, a filamentous BACTERIUM (not a fungus), which is an oral commensal that invades through tissue breaches after trauma or extraction, producing sulfur granules.

Note: The three inhaled dimorphic fungi worth knowing together: HISTOPLASMOSIS (bird and bat droppings, Ohio/Mississippi valleys), BLASTOMYCOSIS (moist soil, same regions) and COCCIDIOIDOMYCOSIS (arid dust, American southwest). All three can produce chronic oral ulcers that are mistaken for malignancy.