A Case Series of Patients With Eczematous Eruptions Following IL-17 Inhibitor Treatment for Psoriasis Vulgaris

Psoriasis vulgaris and eczema are characterized by an imbalance in the Th1 and Th2 immune response and distinct cytokine profiles, where Th1 is more prominent in psoriasis and Th2 is more prominent in eczema. A common treatment for psoriasis is anti-IL-17 therapy, in which inhibition of IL-17 cytokines and the Th1/Th17 immune response may cause a paradoxical shift favoring the Th2 immune response and an eczematous phenotype. Our case series presents three patients who developed a cutaneous eczematous eruption 8-12 weeks following treatment of psoriasis with an IL-17 inhibitor (secukinumab, ixekizumab, or brodalumab) suggesting this phenomenon of shifting cytokine levels away from the phenotype of psoriasis toward the opposing disease.