Background Axial spondyloarthritis (SpA) is associated with several extra-articular manifestations such as the skin disease psoriasis. On the other hand, SpA was found to be more prevalent (3–4%) in patients with another skin disease: hidradenitis suppurativa (HS).¹ HS is a chronic, recurrent, debilitating inflammatory skin disease that involves deep-seated painful nodules in the inverse body regions, with an average prevalence of 1% in the European population and a female predominance (ratio 3:1).² Thus far, the prevalence of HS in axial SpA is not exactly known.

Objectives To investigate the prevalence of HS in patients with axial SpA.

Methods A self-screening questionnaire with validated questions concerning HS signs and symptoms including prototypical pictures was send to all participating patients from the Groningen Leeuwarden axial SpA (GLAS) cohort in 2016. All patients fulfilled the ASAS axial SpA criteria. Self-reported HS symptoms were verified by checking medical records and/or verification by phone, defined as diagnosis of HS by a dermatologist.

Results In total, 588 questionnaires were send to the GLAS patients, of which 459 were returned and could be included in the final analysis (response rate 78%). Of the included patients, mean age was 50±13 years, 63% were male, mean symptom duration was 23±13 years, and 78% were HLA-B27 positive.

The questionnaire data showed a high self-reported HS prevalence of 11%. HS symptoms were confirmed by doctor's diagnosis in the large majority of these patients (41/50; 82%), resulting in an estimated HS prevalence of 9%.

The next step will be the comparison of patient characteristics and clinical assessments between axial SpA patients with and without HS.

Conclusions The present observational cohort study shows that HS is a common skin disease in patients with axial SpA.

References

1. Richette et al. J Rheumatol 2014;41(3):490–4.

2. Zouboulis et al. J Eur Acad Dermatol Venereol 2015;29(4):619–44.

References

Disclosure of Interest None declared