These common small oval painful mouth ulcers arise, usually without an obvious cause, most often in ‘movable mucosae’ such as the gutters of the mouth, tongue or cheek (Fig. 13.33). An area of tenderness changes into a small red papule that quickly turns into a grey 2–5 mm painful ulcer with a red areola. Herpetiform aphthae occur in groups of 2–5 tiny painful ulcers. Major aphthae (periadenitis mucosa necrotica) are usually larger than 1 cm across and tend to appear in the back of the mouth.
Small ulcers heal in a week or two; the pain stops within days. Major aphthae may persist for months.
Recurrent herpes simplex infections mimic herpetiform apthae but, in the latter, cultures are negative and blisters are not seen. Behçet’s disease causes confusion in patients with major aphthae. In fact, a diagnosis of Behçet’s is often wrongly made in patients with recurrent aphthae of all sorts, when the patient has some other skin disease or joint pain. Patients with true Behçet’s disease should have at least two of these other findings: genital ulcers, pustular vasculitis of skin, synovitis, uveitis or meningoencephalitis.
Usually none are needed. Occasional associations include Crohn’s disease, ulcerative colitis, gluten-sensitive enteropathy, cyclical neutropenia, other neutropenias, HIV infection, and deficiencies of iron, vitamin B12 or folate.
Prevention is best. Trauma, such as aggressive tooth brushing, hard or aggravating foods and stress should be avoided if relevant. The application of a topical corticosteroid gel, such as fluocinonide, to new lesions may shorten their course. In severe or complex cases, consider referral.