Eczematous Vesicular Rruption and Exacerbation of Chronic Spontaneous Urticaria Associated with Secukinumab

The pathogenesis of chronic spontaneous urticaria (CSU) is complex. Though the involvement of functional autoantibodies and imbalance of T helper (Th) cell subsets have been reported, the exact mechanism remains elusive. We report a case of eczematous vesicular eruption and exacerbation of CSU in a patient with psoriasis after treat¬ment with secukinumab, an anti-interleukin (IL)-17 monoclonal antibody. The eczematoid eruption subsided after the administration of systemic steroids, but the exacerbation of CSU was not controlled. After switching the therapy to guselkumab, an anti-IL-23 monoclonal antibody, to supplement the control of the psoriasis lesions, the patient's urticaria flare-ups were well controlled with only HI antihistamines. We hypothesize that the Th2-skewed immune response induced by anti-IL-17 treatment in predisposed patients might have resulted in the eczematous eruption and exacerbation of CSU. (Korean J Dermatol 2022;60(9):611~614).