P#22  Histological features of peripilar signs during alopecia

C. Deloche1, O. de Lacharrière1, C. Misciali2, B.M. Piraccini2 C. Vincenzi2, P. Bastien1 and A. Tosti2. 1L'Oréal Recherche, Clichy, France, 2Dept of Dermatology, University of Bologna, Bologna, Italy

Recently, we described peripilar signs (PPS) during androgenic alopecia. Our purpose was to establish a correlation between PPS observed during alopecia and histological features. Forty-two subjects (21 men and 21 women) with a clinical diagnosis of alopecia were involved in the study. On each subject, macrophotographs were taken on a delineated vertex area with a Dermaphot® camera (magnification X4). A 4 mm punch biopsy sample was obtained from the photographed area and then horizontally cut for quantitative assessment of histological pattern. Histological analysis showed that PPS were mainly related to perifollicular infiltrates (PFI) (p=0.06). However, cellular infiltrates were not the only pattern linked to PPS; epidermal thickness was also modified. When PFI score was severe (more than median score), epidermal thickness was increased (p=0.003); in contrast, when PFI score was low (less than median score), an epidermal thinning was observed. We assume that these histological observations which associate inflammatory signs and epidermal changes, represent the histological features of peripilar signs associated with the alopecia process as previously reported.