Baseline Characteristics from UNITE: An Observational, International, Multicentre Registry to Evaluate Hidradenitis Suppurativa (Acne Inversa) in Clinical Practice

Background: Hidradenitis suppurativa (HS), also known as acne inversa, is a recurring, painful, chronic, and sometimes disfiguring inflammatory skin disease. Objectives: Our objective was to report the baseline clinical characteristics, natural history, and associated outcomes of patients with HS from the ongoing, prospective, non-interventional UNITE registry that is collecting data regarding the natural history and associated outcomes of HS. Methods: Patients with inflammatory HS lesions were enrolled, including adolescents (aged 12 to < 18 years) and adults (aged ≥ 18 years). None had participated in previous or current originator-adalimumab studies/registries. Patients received treatment consistent with site-specific, routine clinical practice. HS disease status was assessed by HS lesions and disease flare; treatment and outcomes data were collected at enrolment and every 6 months for ≤ 4 years. Results: Enrolment (N = 594; 89.1% adults; 10.9% adolescents) occurred from 29 October 2013 to 29 December 2015 at 73 sites in 12 countries. At baseline, the majority were female (69.7%) and White (81.2%), had moderate-to-severe disease (Hurley stage II or III; 93.3%), and had undergone prior procedures/surgery for HS (68.7%). In total, 61.6% of adults and 49.2% of adolescents were obese; 40.2% of patients reported current tobacco use. Scarring due to lesions occurred in 91.2% of patients. The prevalence of comorbidities of interest was as follows: depression (13.3%), other psychiatric disorders (9.6%), inflammatory bowel disease (2.7%), diabetes (9.1%), and polycystic ovary syndrome (5.2%). Conclusions: In this population from the UNITE HS registry, obesity and smoking were common, and disease burden was high, manifesting as multiple lesions, scarring, surgical history, and considerable comorbidities.