Rosacea-like demodicosis mimicking cutaneous lymphoma.

© 2012 The Authors. doi: 10.2340/00015555-1200 Journal Compilation © 2012 Acta Dermato-Venereologica. ISSN 0001-5555 Demodex mites may play a pathogenic role when present in excessive numbers or when penetrating into the dermis. There are two types of mites. Demodex folliculorum is usually found in the follicular infundibulum, and D. brevis in sebaceous ducts and meibomian glands (1, 2). Pityriasis folliculorum is one of the typical skin manifestations of Demodex, and is characterized by facial erythema with follicular plugs and scale producing a “nutmeg-grater” or “sandpaper-like” appearance. Histologically, the eruption exhibits perivascular and diffuse dermal infiltration of lymphocytes without granuloma formation. Rosacea-like demodicosis is another representative eruption characterized by follicular scaling, sudden onset, rapid progression, and no history of flushing (3, 4). In addition, meibomian gland dysfunction and keratoconjunctivitis may occur as eye lesions (5). Notably, there may be eyelid involvement, called demodectic blepharitis. Biopsies show a primary perifollicular infiltrate of mononuclear cells, with possible granulomatous inflammation. Demodicosis gravis represents a more severe form of demodicosis and shows intriguing granulomatous rosacea. Biopsies show granulomas with central caseation necrosis and foreign-body-type multinucleated giant cell (3, 4). We report here two patients with rosacea-like demodicosis who had indurated lesions with massive lymphocytic infiltrates on the eyelids, forehead and cheeks and congestion of the eyes.