Injection site reactions resulting from the use of biological therapy in the treatment of moderate-to-severe plaque psoriasis

INTRODUCTION: Biological medications have significantly improved the prognosis of psoriasis patients. All biological drugs (except infliximab) for psoriasis require subcutaneous (SC) administration. Adverse events of biologic drug treatment include injection site reactions. ISRs are a local phenomenon characterized by swelling, erythema, pruritus, and pain around the injection site. AREAS COVERED: We conducted a review to analyze the differences between the ISRs of various biologics approved for psoriasis. Specifically, the review focused on anti-TNF-α, anti-IL12/23, anti-IL-17, and anti-IL-23 drugs. EXPERT OPINION: Etanercept and adalimumab have reported ISR rates of 37% and 20%, respectively, with erythema, pruritus, pain, and irritation being the most common. Citrate free (CF) solution and thinner needles have reduced ISR associated with adalimumab. Ustekinumab showed a low risk of ISR. Regarding secukinumab and ixekizumab, pain was found to be the most common ISR. The introduction of CF ixekizumab formulation has shown promise in reducing ISRs associated with ixekizumab. The risk of ISR appears insignificant with bimekizumab, brodalumab, and anti-IL23 drugs, with ISR rates ranging from less than 1% to 7.1%. The choice of biologic agent should consider ISR risk. Education on injection techniques and the use of single-dose autoinjectors/pens can mitigate ISR risk.