TBA (16S168)

Anti-TNFa antibody induced Psoriasis in patients with Inflammatory Bowel Disease; a prospective Irish cohort study


S Kirthi1, AM Tobin1, D McNamara1=


1. Trinity Academic Gastroenterology Group (TAGG), Trinity College Dublin

2. Department of Dermatology, Tallaght Hospital


The increased use of anti-TNFα antibody in Inflammatory Bowel Disease(IBD) has generated interest regarding the paradoxical triggering of psoriatic skin lesions in its users.


To determine the prevalence of psoriasis in an IBD cohort with reference to clinical characteristics and anti-TNFα use.


Following ethical approval,a survey questionnaire that included demographic and clinical data including age,gender,smoking status,IBD type,diagnosis of psoriasis and anti-TNFα use was posted out to all patients attending the IBD clinic in Tallaght Hospital.Incidence rates of concomitant and reactive psoriasis were analysed using a students T-test,p<0.05 was significant.


In all,905 questionnaires were posted out,34%(n=312) returned,32%(n=286)were complete.In all,58% (n=166)were female,36%(n=103) and 64%(n=183) had UC and CD respectively,55%(n=157) ever smoked,44%(n=126) were ever on an anti-TNFα therapy of which 56% (n=71)had been on Adalimumab(ADA)only,18%(n=23)Infliximab(IFX) only,23%(n=29)on ADA or IFX,and 2%(n=3)were exposed to Symponi.In all,55.3%(n=57) and 54.6%(n=100) of the UC and CD cohort smoked.The overall prevalence rate of IBD and psoriasis was 9.4%(n=27),mean age 48 years(range 33-66)of which 30%(n=8)had reactive psoriasis, ie psoriasis occurring after commencement anti-TNFα therapy.The mean duration of treatment before onset of reactive psoriasis was 2.6years. The prevalence rate of psoriasis in the non-biologic and biologic cohort was 11.9%(19 of 160)and 6.3% (8 of 126) respectively, p=0.1, CI=1.82to12.57. There was a similar rate of the overall prevalence of IBD and psoriasis 9.4% (27 of 286) compared to reactive psoriasis 6.3% (8 of 126), p=0.31,CI =3.52 to 8.40 in our cohort.Interestingly,all 8 patients who had reactive psoriasis had CD and were female compared to 63%(17 of 27)CD and females in the overall psoriasis group,p=0.04, CI = 3.93to57.59. There was no association between the type of AntiTNFα prescribed with the occurrence of reactive psoriasis 6%(6 of 100) vs. 3.8%(2 of 52) ADA and IFX respectively, Odds Ratio(OR)=1.5,p=0.59, 95% CI 0.30to8.00 or smoking with any form of psoriasis in IBD,OR=1.4, p=0.42,CI= 0.6182to3.1560.


In our study,there was a similar prevalence rate of reactive psoriasis and background rate of psoriasis in the overall IBD cohort(6.3%vs9.4%).Our study suggests that the risk factors associated with reactive psoriasis include a diagnosis of CD and female gender. Further work to elucidate the pathophysiology of this phenomenon is required.