Perioral dermatitis.

Perioral dermatitis is a relatively common inflammatory disorder of facial skin, often appearing in patients with rosacea, but with less inflammation. A typical perioral dermatitis presentation occurs with the eruption of papules and pustules confined to the nasolabial folds and the skin of the chin. Clinically, small pink papules and pustules may recur over weeks to months, sometimes with fine scales. The differential diagnosis includes seborrheic dermatitis, systemic lupus erythematosus, acne vulgaris, lupus miliaris disseminatus faciei, steroid-induced rosacea, and even basal cell carcinoma. The histopathology is similar to that found in rosacea. With advancement of the process, a perivascular and perifollicular lymphohistiocytic infiltrate develops. Sebaceous hyperplasia may be prominent in some patients. The most severe forms of disease show perifollicular noncaseating epithelioid granulomas. Treatment may include topical metronidazole as for rosacea (once or twice daily), azelaic acid cream, benzyl peroxide preparations, and to a lesser degree, topical erythromycin, clindamycin, or tetracycline. Oral tetracycline, doxycycline, or minocycline may also be helpful in presentations that are more resistant.