PATIENTS with the skin condition hidradenitis suppurativa (HS) should be screened in rheumatology for subclinical spondyloarthritis (SpA), according to a real-world study. Having both is not uncommon, and diagnosis would have important implications for treatment, researchers say.
Prevalence and Detection of SpA in Patients with HS
In the prospective, cross-sectional study, researchers evaluated 120 adults with a confirmed diagnosis of HS for musculoskeletal signs of SpA. They performed a clinical examination to look for inflammatory back pain, peripheral arthritis, and enthesitis. Patients also underwent MRI to screen for sacroiliitis and enthesitis, and lab tests for C-reactive protein, erythrocyte sedimentation rate, and human leukocyte antigen B27 (HLA-B27) status.
The most common SpA-related musculoskeletal finding was clinical enthesitis (18.3%), followed by MRI-detected sacroiliitis (13.3%), positive HLA-B27 status (12.5%), and peripheral joint involvement (10%). Study authors noted that enthesitis is a ‘key pathological hallmark of SpA’ that may be easily overlooked by dermatology providers.
Dual Diagnosis, HS+SpA, Guides Treatment
Based on the results, which show that axial and peripheral SpA features like sacroiliitis and enthesitis were “not uncommon,” the study authors recommend that patients with joint-related symptoms should be referred for a rheumatology evaluation. It’s important to get referred and diagnosed as early as possible so patients can get the most appropriate treatment, they suggested. In the study, MRI was able to pick up early inflammatory lesions, before patients develop structural damage, they pointed out.
The study adds to a growing speculation that HS and SpA have similar underlying mechanisms and that patients with both skin and musculoskeletal effects could benefit from treatment with available biological therapies targeting IL-17 and IL-23 pathways. These biologics were appropriate for the patients in the study, but only 10% had been treated with the IL-17A inhibitor secukinumab, and none had received IL-23 inhibitors.
Researchers did not find a statistically significant association between the severity of HS and SpA-related outcomes, which explains why musculoskeletal involvement might get missed in dermatology assessments. Dermatologists and rheumatologists should be collaborating more on treatment plans to ensure evaluation of inflammatory joint disease in patients with HS, the data suggest.
These findings collectively emphasize the need for musculoskeletal screening in HS populations, including those without overt rheumatologic complaints, according to the researchers.
Reference: Bakay U and Bakay ÖSK. Subclinical spondyloarthritis features in patients with hidradenitis suppurativa: A real-world cross-sectional analysis. J Clin Pract Res 2025;47(5):480-5.
Author
Emily Hayes, Freelance Writer and Editor
