Acute oral ulcers.

Accurate diagnosis of acute oral ulcers can be challenging. Important historic details include the pattern of recurrence, anatomic areas of involvement within the mouth and elsewhere on the mucocutaneous surface, associated medical symptoms or comorbidities, and symptomology. Careful mucocutaneous examination is essential. When necessary, biopsy at an active site without ulceration is generally optimal. Depending on the clinical scenario, supplemental studies that may be useful include cultures; perilesional biopsy for direct immunofluorescence testing; and evaluation for infectious diseases, gluten sensitivity, inflammatory bowel disease, human immunodeficiency virus infection, connective tissue diseases, or hematinic deficiencies. Clinicians should maintain a broad differential diagnosis when evaluating patients with acute oral ulcers.