What is the oral fungal infection that can occur after antibiotic use presenting as white patches on the tongue?

• A. Canker sores
• B. Geographic tongue
• C. Thrush
• D. Oral herpes

Answer: (C)

Antibiotics can disrupt the normal balance of microbes in the mouth, allowing Candida species (the yeast Candida albicans) to overgrow. When this happens, the classic finding is oral thrush: creamy white plaques on the tongue and other mucosal surfaces that may be wiped away to reveal a red, sometimes irritated base. This makes sense after antibiotic use because the protective bacterial flora that normally helps keep Candida in check is diminished.

Other conditions don’t fit the pattern of a fungal overgrowth with white patches. Canker sores are painful ulcers, not white patches on the tongue. Geographic tongue produces irregular, map-like red and pale (white) patterns but isn’t a fungal infection. Oral herpes causes clustered vesicles that crust, not diffuse white plaques.

Thrush is typically treated with antifungal medications, such as topical agents (nystatin or clotrimazole) or a short course of systemic antifungals if needed, along with good oral hygiene and addressing any underlying risk factors.