The Second to Fourth Digit Ratio in the Patients with Hidradenitis Suppurativa

Abstract

Aim: Hidradenitis suppurativa (HS) is a chronic, recurrent, and inflammatory skin disease involving the hair follicles and sweat glands. Based on the link between androgens and the second to fourth digit ratio (2D:4D) and also the connection between sex hormones and HS, it can be stated that there is an association between HS and the 2D:4D ratio. Based on this hypothesis, the present study investigated the relationships between HS, the 2D:4D ratio, and sex hormones. Materials and methods: Total testosterone and dehidroepiandrosteron-sulfate (DHEA-S) levels were measured in both male and female cases and controls. Luteinizing hormone (LH), follicle-stimulating hormone (FSH), LH/FSH ratio, estradiol, progesterone, and prolactin levels were analyzed in only female cases and controls. The 2D:4D ratio was calculated by dividing the second finger's length by the fourth finger's length. Results: One hundred eight patients were diagnosed with HS. Eighty of these patients (39 female) were enrolled and constituted the study group. The control group consisted of 70 healthy participants (35 female). There were significant associations between weight, body mass index, smoking status, duration of smoking, and the length of left 2D and left 4D in both female cases and controls. We also found significant relationships between body mass index, smoking status, duration of smoking, and total testosterone in male cases and controls. In female cases, we determined significant correlations between the length of the DHEA-S and 2D right, 4D right and 2D left. In male patients there were significant associations between age of disease onset and right 2D:4D, age of disease onset and left 2D:4D, disease duration and right 4D length, disease duration and left 2D length, DHEA-S and right 4D length, DHEA-S and left 2D length. Conclusion: We suggest that our research is a valuable contribution to the literature since it is the first study assessing the relationships between the 2D:4D ratio, HS and circulating hormone levels. However, further prospective studies, including larger patient samples, are required to identify relationships between the 2D:4D ratio and HS.