Recurrent aphthous stomatitis is a common problem with 20% to 50% of the population having experienced simple aphthous lesions (ie, canker sores). Complex aphthosis is the diagnosis given to patients with almost constant >3 oral aphthae or recurrent oral and genital aphthae in the absence of Behçet's disease.

Eighty-one patients were referred to the Wake Forest University School of Medicine, Department of Dermatology from 1995 to 2001 with the diagnosis of presumptive Behçet's disease. After exclusion of patients with simple recurrent aphthous stomatitis or non-aphthous oral disease, 64 patients remained. Ten of the patients met criteria for Behçet's disease. The remaining 54 patients were evaluated and treated as patients with the diagnosis of complex aphthosis.

The 54 patients with complex aphthosis became the subject of this study. Twelve patients had secondary complex aphthosis with 10/12 having inflammatory bowel disease. The remaining 42 patients had primary (ie, idiopathic) complex aphthosis. The therapeutic ladder for these patients ranged from topical therapy through oral colchicine and combination oral colchicine and oral dapsone therapy to oral thalidomide therapy.

Complex aphthosis is an important condition to distinguish from Behçet's disease. Appropriate patient evaluation algorithms and treatment therapeutic ladders are proposed.