Background: Hormonal factors have long been proposed to play a role in Behcet's disease (BD). Male sex, systemic onset, HLA-B51 positivity and a younger age of onset in BD are associated with severer disease, and the disease generally runs a milder course in women. Vascular involvement is more common, and the skin pathergy test (SPT) is more strongly positive in men. BD rarely develops before puberty or after the age of 50 years. Clinical manifestations of the disease, with the exception of eye symptoms, tend to improve with time. Therefore, BD may be androgen driven to some degree. Objectives: We aimed to investigate androgen receptor (AR) levels of oral ulcers (OU), genital ulcers (GU) and SPT areas and compared them with those of adjacent normal-appearing skin/mucosa from patients with BD. Methods: Thirty-eight patients with BD (16 female, 22 male; mean +/-SD age, 36.45 +/- 10.2 years), diagnosed according to the criteria of the International Study Group for Behcet's Disease, were included in the study with blind histological examination. Biopsies from OU of 10 patients, GU of 11 patients, SPT areas of 17 patients and adjacent (approximately 2 cm distant) normal-appearing skin/mucosa in patients with BD were performed. Nuclear AR levels were studied by an immunohistochemical technique, using monoclonal antibodies. The percentage of positively staining cells was recorded as the AR index (ARI). In addition, the prevalence and the positivity rate of SPT has also been evaluated. Results: ARI values in the lesional and control (non-lesional adjacent) skin/mucosa were found to be 14.5 versus 18% for OU, 28.7 versus 25.5% for GU and 36.3 versus 21.8% (p = 0.068) for SPT areas. The positive SPT areas in male patients showed a higher ARI than those of female patients (43.36 and 23.33%; p = 0.078). The ARI values of SPT areas in male patients but not in female patients were found to be significantly higher as compared with non-lesional skin (21.63%; p = 0.039). The SPT positivity was also more common in male patients compared with female patients (86.4% and 62.5%), although the difference was not significant (p = 0.88). SPT have been found to be more strongly positive among the males (4.63 +/- 3.3) compared with female patients (3.18 +/- 1.9), and the difference was statistically significant (p = 0.022). Conclusions: Our findings indicate that androgens seem to play a role both in the formation and increased positivity of the SPT areas in male patients with BD. Copyright (C) 2005 S. Karger AG, Basel.