Back pain is a painful condition that commonly affects the lower part of the spine. The axial spondyloarthropathy (SpA) refers to a part of spondyloarthriticharacterized by back pain, and radiographic sacroiliitis might or might not be present but  radiographic sacroiliitis is present on plain X-rays.

Hidradenitis suppurativa (HS) is a chronic inflammatory disease, generating fistulating sinuses in the intertriginous skin of axillary, genitofemoral and perianal sites. The current study by Schneider-Burrus S et al aimed to understand and identify the prevalence of back pain and SpA in HS patients as other chronic inflammatory diseases, like psoriasis.

The study employed a prospective questionnaire survey in 100 HS patients and a retrospective evaluation of pelvic magnetic resonance imaging (MRI) scans in 46 HS patients.

According the reported study results, 71% of HS patients were suffering from back pain. Results were similar irrespective of disease duration, age at onset of HS, body mass index (BMI) or disease severity between HS patients with and without back pain. About 32.6 % of HS patients showed signs of chronic SpA and 39.1% signs of active SpA. No important differences between patients with or without SpA were reported concerning age at time of MRI, age at onset of HS, duration of disease, smoking habits, and BMI. Also, there was no correlation between these parameters and the degree of SpA.

Only patients with moderate or severe HS (Hurley stage II and III) in genitofemoral/perianal sites were assessed via MRI scans.

Therefore, it can be concluded that back pain and SpA are very common among patients with moderate or severe HS. Neither medical history nor clinical parameters provide hints for the occurence of SpA.