Demodex folliculorum and skin disease: A case-control study

Abstract

Demodex mites are commensals of the pilosebaceous unit in human. This study aimed to investigate possible association ofDemodex folliculorum with Basal Cell Carcinoma (BCC), Squamous Cell Carcinoma (SCC), melanoma, Discoid Lupus Erythematosus (DLE) and rosacea. In this case-control study, standardized skin surface biopsy samples were obtained from the cheeks of healthy individuals (n = 28); patients with BCC (n = 18), SCC (n = 13) and melanoma (n = 11) and patients with DLE (n = 28) and inflammatory rosacea (n = 34). Mite density (cm-2) and the rate of infestation (density >5) were compared. The rate of mite infestation (%) was comparable between the controls (21.4) and the patients with BCC (22.2, p = 0.95), SCC (18.8, p = 0.83), melanoma (9.1, p = 0.37) and DLE (17.9, p = 0.74). Infestation was significantly more frequent in the rosacea group (47.1, p = 0.04) than in the controls. While, the mean mite density (cm-2) was comparable between the control (4.07آ±2.06) and the groups with BCC (5.01آ±2.08,p= 0.68), SCC(3.17آ±1.29,p = 0.49)andDLE(3.26آ±1.04,p = 0.91); it was significantly higher in the group of rosacea (8.56آ±3.29, p = 0.03) and lower in the group of melanoma (1.45آ±0.58, p = 0.04) in comparison with the normal group. In conclusion, although Demodex folliculorum does not seem to play a role in the pathogenesis of BCC, SCC and DLE, it is apparently associated with rosacea and melanoma.