Hidradenitis Suppurativa Prevalence in Santiago, Chile.

Background: The worldwide prevalence of hidradenitis suppurativa (HS) still remains unknown. In Latin America, there are scarce data regarding the prevalence of HS and in Chile, we do not have information about it. The aim of this study was to estimate the prevalence of HS in Santiago, Chile.

Methods: This study is part of the Global Hidradenitis Suppurativa Atlas (GHiSA) initiative. It was a multicenter center study in secondary care in Santiago, Chile. The inclusion criteria were apparently healthy adults accompanying a patient to the health center that were approached in the waiting room of internal medicine or pediatrics departments. A previously validated screening questionnaire for HS was used. Screen-positive and randomly selected screen-negative participants were clinically examined.

Results: 500 participants were included. The prevalence of HS in the sample was 2.4% (12/500; 95% CI: 1.4%-4.1%). In the HS group, all were female (100%; p = 0.019), with a median age of 35.5 years (p = 0.089) and 25% were smokers (p = 1). Body mass index (BMI) of patients with HS was significant higher than non-HS patients (30.9 kg/m2 and 28.1 kg/m2, respectively; p = 0.028). Axilla and groin were the predominant sites of affection (58.3% each one). 75% of HS patients were classified as Hurley stage I and 25% as Hurley stage II.

Conclusion: The estimated prevalence of HS in Santiago of Chile was 2.4%, which is high compared to other previous reports worldwide but similar to other countries participating in the GHiSA initiative. In our study, we only had female patients with HS, suggesting a clear predominance of women suffering HS in Chile. A high BMI appears to be a risk factor for HS in our population. The screening questionnaire for HS is a suitable tool for population surveys.