A 2-year-old girl was withdrawn from a day care center for excessive irritability On physical examination, she has multiple, small superficial ulcers of the oral mucosa. The ulcerations heal spontaneously over the next 5 days. Which of the following is the most likely diagnosis?

Aphthous stomatitis describes a common disease that is characterized by painful, recurrent, solitary or multiple, small ulcers of the oral mucosa. The causative agent is unknown. Microscopically, the lesion consists of a shallow ulcer covered by a fibrinopurulent exudate. Candidiasis (choice B) features white plaques.Diagnosis: Aphthous stomatitis