Prevalence and factors associated with hidradenitis suppurativa: results from two case-control studies

BACKGROUND: Conflicting opinions have been reported regarding the epidemiology of hidradenitis suppurativa.

OBJECTIVE: We sought to evaluate the prevalence of hidradenitis suppurativa and to identify associated factors.

METHODOLOGY: Prevalence was evaluated using a representative sample of the French population (n=10,000). Associated risk factors were assessed using two case-control studies, one population-based with 67 self-reported patients and 200 control subjects, and the other clinic-based with 302 medically assessed patients and 906 control subjects.

RESULTS: The prevalence was 1% of the French population. Multivariate analyses showed a strong association with current smoking in self-reported (odds ratio=4.16, 95% confidence interval [2.99-8.69]) and in medically assessed (odds ratio=12.55 [8.58-18.38]) populations. Association with body mass index was significant in medically assessed patients (odds ratio=1.12 [1.08-1.15]) for each increase of 1 U of BMI.

LIMITATIONS: A causal relationship could not be established with such a cross-sectional study.

CONCLUSION: Hidradenitis suppurativa is a common disease, frequently associated with smoking and being overweight.