Demodex mites in acne rosacea

The hair follicle mites Demodex folliculorum and Demodex brevis and their r ole in the pathogenesis of rosacea have been the subject of much debate in the past. We studied the prevalence of Demodex mites in facial skin biopsie s obtained from 80 patients with rosacea, 40 with facial eczematous eruptio n and 40 with lupus erythematosus discoides. The mite prevalence in the ros acea group (51%) was significantly higher than in the rest of the study pop ulation (eczema 28% and lupus discoides 31%). Demodex mites were found on a ll facial sites. The most infested areas in the whole study group were the forehead (49%) and the cheeks (44%). Males were more frequently infested (5 9%) than females (30%). We did not find any significant difference in mite counts of infested follicles between rosacea and the control group. A lymph o-histiocytic cell infiltration was seen around the infested hair follicles . Our results suggest that Demodex mites may play a role in the inflammator y reaction in acne rosacea.