Which organism is commonly associated with yeast infections such as oral thrush, diaper rash, and endocarditis in IV drug users?

• A. Aspergillus fumigatus
• B. Candida albicans
• C. Cryptococcus neoformans
• D. Malassezia sp

Answer: (B)

Candida albicans is the yeast most commonly linked to mucosal and skin yeast infections like oral thrush and diaper rash, and it can also cause endocarditis in people who inject drugs. Candida is a commensal organism that can overgrow when normal flora is disturbed, leading to oral and diaper-area infections. In IV drug users, bloodstream invasion by Candida can seed heart valves, especially the tricuspid valve, causing fungal endocarditis, which boards often associate with this organism.

The other organisms don’t fit these clues as well. Aspergillus fumigatus is a mold that typically causes pulmonary disease in immunocompromised patients. Cryptococcus neoformans is a yeast that classically causes meningitis in those with weakened immunity. Malassezia species cause superficial skin conditions such as seborrheic dermatitis or tinea versicolor, not mucosal infections or endocarditis.