Hidradenitis Suppurativa in the Pediatric Population: An International, Multicenter, Retrospective, Cross-sectional Study of 481 Pediatric Patients.

Importance: Hidradenitis suppurativa (HS) in pediatric patients has been understudied. Increased awareness and recognition of HS prevalence in children demand efforts to better understand this condition.
Objective: To describe the demographics, clinical features, treatment, associated comorbidities, and outcomes in a large cohort of pediatric patients with HS.
Design, Setting, and Participants: International, multicenter, retrospective medical record review of pediatric patients (aged 1-18 years) with a clinical diagnosis of HS carried out in 10 dermatology clinics across the US, Canada, Israel, Australia, and Italy from January 1996 to January 2017.
Main Outcomes and Measures: Patient demographics, clinical features, severity, associated comorbidities, and treatments in pediatric patients with HS.
Results: This cross-sectional study included 481 patients diagnosed with HS. Overall, 386 (80%) were girls. The mean (SD) age of disease onset was 12.5 (2.9) years, and the mean (SD) age at diagnosis was 14.4 (3.5) years. Family history of HS was present in 111 of 271 (41%) patients. First signs/symptoms reported at disease onset were cyst/abscess in 229 of 481 (48%), pain/tenderness in 118 of 481 (25%), and papules/pustules in 117 of 481 (24%). At initial dermatologic assessment, 233 of 481 (48%) patients already had evidence of skin scarring. Disease severity (Hurley staging) was documented in 288 of 481 (60%) patients (47% stage 1, 45% stage 2 and 8% stage 3). Comorbid conditions were reported in 406 of 481 (85%) patients, the most common being obesity (263/406 [65%]) and acne vulgaris (118/406 [29%]). Complications occurred in 378 of 481 (79%) patients, the most common of which were scars or contractures (301/378 [80%]).
Conclusions and Relevance: The findings of this study indicate that there is a gap in recognizing and diagnosing pediatric HS. Pediatric patients with HS are likely to present with other comorbidities. Prospective observational and interventional studies are needed to better understand clinical course and optimal treatments for pediatric HS.