A recent study suggests that the appearance of hidradenitis suppurativa may be another associated manifestation that can predict a more severe course of axial spondyloarthritis.
The presence of extra-articular manifestations (EAMs) in axial spondyloarthritis (SpA) such as uveitis, psoriasis, and inflammatory bowel disease are frequently used to support the initial diagnosis and make treatment decisions. A recent study reported by Rondags et al. in Seminars in Arthritis and Rheumatism suggests that the appearance of hidradenitis suppurativa (HS) may be another associated manifestation that can predict a more severe course of SpA.
A higher prevalence of SpA has been reported in patients with HS, a chronic inflammatory skin disease producing disfiguring scarring and painful nodules at the terminal site of hair follicles, usually at the underarms, buttocks and groin regions. At the same time, heel enthesitis and dactylitis-both common features of SpA-have been associated with HS as well.
In the current study, investigators from the Netherlands examined the inverse correlation of HS in SpA using a screening questionnaire sent to all qualifying patients in the Groningen Leeuwarden Axial Spondyloarthritis (GLAS) cohort.
A total of 449 questionnaires were included in the final analysis, representing 76% of the SpA cohort. The questionnaire asked for answers about current and past presence of HS symptoms, with pictures of the Hurley stages of HS and descriptions of lesions. Forty-seven of the 449 respondents were positive for a self-diagnosis of HS, and 3 had dermatologist confirmed diagnoses, for an overall prevalence rate of 9.1%.
The study found that SpA patients with HS were significantly more likely to be female and had greater self-reported SpA disease activity and worsened quality of life, compared to SpA patients without HS. The HS/SpA patients also showed trends toward being overweight and were more likely to be current or past smokers than those without HS.
The prevalence of HS in SpA patients in this study was 1.7 times that of the general population without SpA, supporting a bilateral correlation between the two diseases. Additionally, the authors suggest a potential shared pathology, supported by evidence from limited case control trials. They recommend that clinicians increase vigilance for HS symptoms in patients with SpA, particularly in female patients who are overweight and those who smoke. “The high prevalence and shared denominators in the pathogenesis and treatment may cautiously suggest that HS could be another EAM in (axial) SpA,” they concluded.
Rondags A, van Straalen KR, Arends S, et al. High prevalence of clinical spondyloarthritis features in patients with hidradenitis suppurativa. J Am Acad Dermatol 2019 Feb;80(2):551-554.e1. doi: 10.1016/j.jaad.2018.06.028. Epub 2018 Dec 14.