A 61-year-old man has a 3-month history of a persistent irritation at the corners of his mouth. He has type 2 diabetes mellitus and is being treated with insulin. Otherwise, he is in good health.

Figure. Erythema, edema, and fissuring at the corner of the mouth.

On examination, there is erythema, edema, and fissuring at the corner of the mouth. There are no satellite papules or pustules. On the tongue there is a fine white film (figure).

Differential diagnosis

Consider diseases that produce inflammation at the corner of the mouth (angular cheilitis).

Allergic contact dermatitis can cause erythema, edema, and fissuring at the corners of the mouth. This can occur when medications (eg, topical neomycin) for presumed infections are applied. The sharp demarcation of the process makes this less likely.

Irritant angular cheilitis is common in elderly patients because as one ages, the architecture of the mouth changes such that there is a persistent fold in the corner of the mouth, which collects irritants (eg, saliva, food). The morphology of this case is identical to that of irritant angular cheilitis, but would not explain the changes on the tongue.

Vitamin deficiency, particularly riboflavin deficiency, may cause angular cheilitis in a pattern similar to what is seen here. The patient's otherwise good health and normal appearance would diminish this diagnosis.

Seborrheic dermatitis can produce inflammatory papules and plaques in the folds of the skin of the face, including the nasolabial fold and the corners of the mouth. However, this process seldom causes a fissure and does not involve the oral mucous membranes, such as the tongue.

Candidiasis with angular cheilitis (perlche) is the correct diagnosis. This problem occurs in diabetic patients, who are prone to candida infections. This typically begins in the mouth as white plaques, as seen on the tongue of this patient, and subsequently affects the corners of the mouth.

The patient was treated with fluconazole, 200 mg, as a single oral dose, which cleared the eruption.

Diagnostic pearl

Angular cheilitis from candidiasis occurs preferentially in patients with diabetes mellitus.

Dr. Levine is professor of medicine (dermatology), University of Arizona Health Sciences Center, Tucson.