A case-control study of hidradenitis suppurativa in an STD population.

The prevalence of hidradenitis suppurativa has been found to be higher among patients attending an STD clinic than in an unselected general population sample. The aetiology of hidradenitis in unknown, but an association with chlamydial infections has been suggested for perineal lesions. Our aim was to describe the history of STD, STD risk factors and possible current STD in patients with hidradenitis. A case-control study comparing patients with hidradenitis (20) and controls (60) was therefore made in patients attending an STD clinic. Genital HPV infection was found to be more common in patients with hidradenitis (p = 0.036), but no differences were seen in the history of STD, STD risk behaviour or other current STD between the two groups studied. HPV infection appears to be the only STD which is more common in hidradenitis patients, but the biological significance of this finding is not clear. It is speculated that common predisposing factors may be responsible. We were unable to support the previously postulated association between Chlamydia trachomatis infection and hidradenitis.