Male sex and a younger age of onset in Behçet's disease (BD) are associated with more severe disease. Eye diseases, folliculitis and thrombophlebitis are also more common among males. The disease rarely developes before puberty or after the age of 50. Clinical manifestations of BD, with the exception of eye symptoms, tend to get better with time. Clinical and histological pattern of the papulopustular lesions (PPL), the most common type of skin lesions in BD and the difference from ordinary acne is contradictory. Therefore, BD may be androgen driven to some degree. In the present study, using acne vulgaris (AV) as a prototype of an androgen driven disease, we investigated such a possibility between PPL and androgen receptor (AR) levels in the sebaceous glands (SG) of PPL from patients with BD and AV.
Eighteen patients with BD (10 women, 8 men; mean +/- SD age, 34 +/- 11 years), 16 patients with AV (10 women, 6 men; mean +/- SD age, 25 +/- 6.2 years), and 10 healthy volunteers (5 women, 5 men; mean +/- SD age, 36 +/- 12 years), were included in this controlled study with blind histological study. Biopsies of the PPL and adjacent (approximately 2 cm distant) normal-appearing skin in patients with BD and AV, and of the normal-appearing skin from healthy volunteers were performed from the interscapular region, thus minimizing differences in androgenic activity. Follicle-based acneiform lesions were excluded for biopsies from patients with BD. Nuclear AR levels of SG were studied by an immunohistochemical technique, using monoclonal antibodies. The percentage of positively staining cells were recorded as the androgen receptor index (ARI).
The lesional skin of the patients with BD showed a higher ARI than non-lesional skin of those patients (34.3% and 23.82%), or the healthy controls (21.37%). AR levels in the lesional skin of active patients was also higher than inactive patients (39.82 and 27.12%), but the differences were not statistically significant. ARI values in the lesional skin (78.58%) of acne patients were found to be significantly higher as compared with non-lesional skin (38.88%) and other groups (p<0.01).
Our findings indicate that androgens may play a role at least in the formation of PPL and disease activity in patients with BD. Androgen metabolism takes place peripherally in the SG, being indipendent of the central endocrine regulation. Target organ sensitivity and excess number of nuclear AR seem to be responsible for the development of AV.