A patient taking prolonged broad-spectrum antibiotics develops white lesions on the palate that can be wiped off, leaving an erythematous (red) base. What is the most likely diagnosis?

The hallmark of acute pseudomembranous candidiasis (oral thrush) is white, curd-like plaques that can be wiped off, leaving an erythematous (red) base that may bleed. This distinguishes it from leukoplakia (cannot be wiped off). Prolonged broad-spectrum antibiotic use is a classic predisposing factor because it disrupts the normal oral bacterial microbiome, allowing Candida albicans to overgrow. The original answer 'Atrophic candidiasis' is incorrect — erythematous/atrophic candidiasis presents as a RED lesion without the characteristic white wipeable plaques. Hyperplastic candidiasis also cannot be wiped off.