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.
Objective: 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.
Limitations: Retrospective design and tertiary care center bias.
Conclusion: 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. Prevalence of arthritis among HS patients across all participating health centers.
- Supplementary figure 3. Exceedance probability distribution of total number of comorbidities per subject by case control-status.

SUPPLEMENTARY TABLES:
- Supplementary Table 1. Inclusion of participants to the study by health center.
- Supplementary Table 2. Descriptive statistics of the affected body locations in patients with HS included in the study.
- Supplementary Table 3. Descriptive statistics of complications in patients with HS included in the study.
- Supplementary Table 4. Comparison of medical events between HS patients with and without concomitant arthritis, both globally and stratified by Hurley stage at diagnostic.
- Supplementary Table 5. Prevalence of concomitant arthritis in patients with HS across participant health centers.