The ulcer is depressed well below the surface, and the inflammation extends deeply. The surface of the ulcer is covered by a fibrinous exudate infiltrated by polymorphs. Beneath is a layer of granulation tissue with dilated capillaries and edema. Deeper still there is a repair reaction, with fibroblasts in the surrounding connective tissue laying down fibrous tissue. Chlorhexidine mouthwashes may help control secondary infection.
Topical corticosteroids remain the mainstay of treatment.
A spectrum of different topical corticosteroids can be employed. At best, topical corticosteroids reduce painful symptoms but not the rate of recurrence of ulcers. Since neither hydrocortisone nor triamcinolone preparations cause significant adrenal suppression, they are popular, but ulcers still recur. Betamethasone, fluocinonide, fluocinolone, and clobetasol are more effective, but they carry the possibility of some adrenal suppression and of predisposing to candidiasis. Topical tetracyclines used alone or in combination with amphotericin may reduce the severity of ulceration, but they do not alter the recurrence rate.