Background Psoriasis is one of the most common extra-articular manifestations in patients with ankylosing spondylitis (AS). TNF inhibitors (TNFi) are highly effective for signs and symptoms of AS and psoriasis. However, there is some evidence about exacerbation or new onset of cutaneous psoriasis during anti TNF therapy.
Objectives To examine the incidence rate of worsening or new onset of psoriasis in AS patients during anti-TNF therapy
Methods AS patients with TNFi were retrospectively analysed in database of patients with biological therapy in Slovakia. This analysis covered AS patients with infliximab, etanercept, adalimumab and golimumab since March 3rd 2003, when the first patient initiated TNFi until December 31st 2013. Duration of anti-TNF treatment was calculated on patient-years (PYs). Disease activity was evaluated by BASDAI, ESR, CRP and global patient assessment of disease activity. History of psoriasis in each patient was explored and worsening of psoriasis or the first episode cases during anti-TNF therapy were analysed. Incidence rate was calculated on 100 PYs, and differences among TNFi were assessed.
Results 385 patients with AS on TNFi were analyzed, of them 327 men (85%) and 58 women (15%). Mean age of patients at the time of initiation of TNF blockers was 39.0 (±10.7) years, median was 37 years (IQR 31-47). Total time on anti-TNF therapy was calculated on 1129 patient-years. 81 patients were exposed to infliximab for a total of 274 PYs, 102 patients were exposed to etanercept for 394 PYs, 155 patients were treated with adalimumab 390 PYs, and 47 patients were under the treatment with golimumab 72 PYs. Cutaneous psoriasis was present in 20 patients (5.2%) in history before starting TNFi – 8 patients on infliximab (9.9%), 8 patients on adalimumab (5.2%), 2 patients on etanercept (2.0%) and 2 patients on golimumab (2.0%). During anti-TNF therapy, exacerbation of cutaneous psoriasis was found only in 2 patients, but first episode cases were described in 6 ones. In every case, dermatologist verified the diagnosis of cutaneous psoriasis, and 50% of all cases had palmo-plantar pustular form of psoriasis, reflecting possible paradoxical reaction of the TNFi. Incidence of paradoxical psoriatic reaction was calculated on 0.71/100 PYs. Relatively more paradoxical psoriatic reactions during anti-TNF therapy were observed in patients with infliximab (1.09/100 PYs) and golimumab (1.41/100 PYs) than in patients with adalimumab and etanercept (both 0.51/100 PYs).
Conclusions Incidence of paradoxical psoriatic effects of anti-TNF therapy in AS patients is very low. Our findings demonstrate that palmo-plantar pustular psoriasis is the most common form of paradoxical skin lesions. They were less frequent in patients treated with etanercept than in patients treated with monoclonal antibodies infliximab and golimumab.
Disclosure of Interest None declared