Disease burden and treatment patterns in patients with hidradenitis suppurativa and concomitant arthritis: a multicenter case-control study

Background: The relationship between HS and arthritis is well-established; however, the impact of their combined disease burden and the associated treatment pattern have not been determined yet. The aim of this study was to assess disease burden and treatment approaches in HS patients with and without arthritis and estimate the prevalence and distribution of arthritis subtypes among HS patients.
Methods: A multicenter, retrospective, case-control study of 272 adults (69 with HS and arthritis; 203 with HS only), matched by sex, age, and HS duration. Data were analyzed using non-parametric tests, linear mixed-effects models, and logistic regression.
Results: Patients with HS and arthritis had higher rates of immune-mediated diseases, including inflammatory bowel disease (OR 9.44, p<0.0001) and psoriasis (OR 2.99, p=0.0038). They exhibited higher DLQI scores (6.30 vs. 4.03, p=0.031), more dermatology visits (7 vs. 5, p=0.0077), and increased biologic therapy use (72.1% vs. 39.9%, p<0.0001). Arthritis prevalence in HS was 1.7% (0.4-4%) in a cohort of 3,644 patients. Spondyloarthritis was the most common subtype, accounting for 66.6% of cases.
Conclusions: HS patients with arthritis have a greater disease burden and higher biologic therapy utilization, emphasizing the need for interdisciplinary care and optimizing resources.

SUPPLEMENTARY FIGURES:
- Supplementary figure 1. Diagram of patient inclusion.
- Supplementary figure 2. Exceedance probability distribution of total number of comorbidities per subject by case control-status.
- Supplementary figure 3. Prevalence of arthritis among HS patients across all participating health centers.

SUPPLEMENTARY TABLES:
- Supplementary table 1. Inclusion of participants to the study by health center.
- Supplementary table 2. Comparison of medical events between HS patients with and without concomitant arthritis, both globally and stratified by Hurley stage at diagnostic.