Background Spondyloarthropathies (SpA) are a group of frequent inflammatory rheumatic disorders with usually delayed diagnosis. Extra articular manifestations such as psoriasis are frequently observed, therefore it is crucial to detect SpA at the dermatologist's clinic.

Objectives The main objective is to evaluate the prevalence of axial SpA in a sample of Lebanese patients with psoriasis. Secondary objectives include evaluating the prevalence of inflammatory back pain (IBP) and peripheral SpA.

Methods We evaluated a sample of consecutive patients, with cutaneous or nail psoriasis, diagnosed by a dermatologist at Hotel-Dieu de France hospital, and a control sample of patients consulting for other dermatologic symptoms. Patients and controls responded to a questionnaire including items corresponding to different sets of SpA criteria. Biology and imaging data were retrieved from the medical file.

Results 80 patients were included, 48 psoriasis and 32 controls. Mean age was 39.3 years (SD 17.66), sex ratio was 1. Mean psoriasis duration was 12.9 years (SD 12.37). 14.6% of psoriasis patients were on systemic treatment, 0% had HLA B27 available, 4.2% had imaging and 12.5% had CRP results. In the psoriasis patients, the prevalence of axial SpA according to the ASAS criteria was 4.2% compared to 0 in the control group. However, according to Amor criteria, where imaging or HLA B27 are not mandatory, the prevalence of SpA was 29.2%, significantly higher than in the control group 0% (p 0.01). The prevalence of peripheral SpA (ASAS criteria) was 27.1%, higher than the control group 0%. The prevalence of IBP according (ASAS criteria) was numerically higher 14.6% in the psoriasis group compared to 3.1% in the control group (p 0.135). No significant correlation was found between age, gender, psoriasis duration and diagnosis of SpA. A statistically significant difference was found between psoriasis duration and IBP prevalence (p 0.049), between family history of SpA and axial SpA (OR 2.18, p 0.003) and IBP (OR 2.38 p 0.027). Nail psoriasis seemed to be associated with peripheral SpA (OR 2.5), however the association was not statistically significant (95% CI 0.62–10.05). The same trend was found for generalized psoriasis: OR 2.47 (95% CI 0.65–9.34).

Conclusions The expected significantly higher prevalence of SpA in the psoriasis sample indicates the importance of raising the awareness of Lebanese dermatologists to early detection of SpA. From simple clinical hints (IBP, family history of SpA, nail psoriasis), the index of suspicion should be high enough to prescribe the appropriate tests and/or refer the patient to a rheumatologist.

1. Rudwaleit M et al. The development of Assessment of SpondyloArthritis international Society classification criteria for axial spondyloarthritis (part II): validation and final selection. Ann Rheum 2009; 68: 777–783.

2. Amor B et al. Critères de classification des spondylarthropathies [in French]. Rev Rhum Mal Osteoartic 1990;57:85–9

3. Rudwaleit M et al. The Assessment of SpondyloArthritis International Society classification criteria for peripheral spondyloarthritis and for spondyloarthritis in general. Ann Rheum 2011 Jan;70(1):25–31

4. Rudwaleit M et al. Inflammatory back pain in ankylosing spondylitis: a reassessment of the clinical history for application as classification and diagnostic criteria. Arthritis Rheum 2006;54:569–78

Acknowledgement Dermatology Department, Hotel-Dieu de France hospital, Beirut

Disclosure of Interest None declared