Majocchi Folliculitis

A 62-year-old woman presented with an itchy, annular eruption on her face of 3 months' duration. A topical antifungal was prescribed, but the slow response to therapy prompted a switch to a topical corticosteroid (triamcinolone 0.1%). The lesion not only failed to clear but became larger.

The patient was otherwise healthy. She had owned cats for many years; this suggested a dermatophyte infection, since household pets frequently are a source of these parasites.

A punch biopsy specimen demonstrated fungal elements and a mononuclear perifollicular infiltrate. These data-together with the history-yielded a diagnosis of Majocchi folliculitis.

Joe Monroe, PA-C, of Tulsa, Okla, notes that the initial medical care provider did not perform a potassium hydroxide (KOH) examination, which could have confirmed the fungal cause of the eruption. Inadequate antifungal therapy resulted in a suboptimal response that engendered diagnostic doubt and led to the use of triamcinolone. The topical corticosteroid slowed the immune response to the dermatophytic infection-in effect, encouraging the infection to become more deep-seated.

In many patients, corticosteroid treatment of a fungal infection can render the lesion unrecognizable (tinea incognito). The corticosteroid also makes it more difficult to confirm the diagnosis with a KOH evaluation, since there is no longer enough scale to collect. Therefore, a punch biopsy with fungal stains often becomes necessary.

The differential diagnosis of Majocchi folliculitis includes nummular eczema, psoriasis, corticosteroid-induced rosacea, perioral dermatitis, and granuloma faciale.

Treatment of this patient's disease consisted of the oral antifungal terbinafine, 250 mg qd for 10 days, and the topical antifungal naftifine gel, bid, until the skin cleared.