Prevalence of hidradenitis suppurativa among patients with Down syndrome: a population-based cross-sectional analysis.

BACKGROUND: Hidradenitis suppurativa (HS) has been linked to Down syndrome (DS).

OBJECTIVES: To determine whether patients with DS have a higher prevalence of HS, and whether the diagnosis of HS occurs at an earlier age for these patients.

METHODS: A cross-sectional analysis was performed for a population sample of 11 936 patients with DS and 16 813 290 patients without DS. The primary outcome was the diagnosis of HS. Systemized Nomenclature of Medicine-Clinical Terms were used to identify patients with DS and HS. We used logistic regression models and significant interaction terms to evaluate the relationship between DS and HS. We also compared the proportion of incident HS cases within 5-year age groups to determine whether patients with DS had received an earlier diagnosis of HS.

RESULTS: Prevalence of HS among patients with DS was 2·1%, compared with 0·3% for patients without DS (P < 0·001). HS prevalence was greatest among patients with DS who were aged 18-29 years. After controlling for age, sex and obesity, there was no difference in the prevalence of HS between female and male patients with DS or between white and nonwhite patients with DS. Compared with patients without DS, patients with DS had increased odds of HS in unadjusted [odds ratio (OR) 7·84, 95% confidence interval (CI) 6·93-8·88] and adjusted (OR 5·24, 95% CI 4·62-5·94) analyses. HS was diagnosed by the age of 29 years in 81·8% of patients with DS, compared with 34·0% of patients without DS (P < 0·001).

CONCLUSIONS: HS is strongly associated with DS across demographic subgroups and may present earlier in life for these patients.