Mepolizumab induced palmoplantar psoriasis: A case report.

BACKGROUND: Atopic dermatitis and asthma are two diseases whose pathogenesis is largely attributable to the activation, at least in the initial stages, of T helper (Th)-2 Lymphocytes, the related cytokine axis, and B lymphocytes with antibody production. Psoriasis is conversely a pathology resulting from a recruitment of Th-17 and Th-1 lymphocytes, after an initial role of innate immunity. Mepolizumab is a humanized monoclonal antibody directed against interleukin (IL)-5, a central cytokine in the Th-2 axis, therefore involved in the pathogenesis of asthma. Several authors have described the appearance of psoriatic lesions in patients with asthma or atopic dermatitis following the therapy with dupilumab, a monoclonal antibody that blocks the interleukin (IL)-4, another Th-2 cytokine. CASE SUMMARY: We present the case of a 59-year-old patient who developed psoriasiform lesions on the palms after mepolizumab therapy for asthma, for the activation of the parallel cytokine cascade after the blockade of IL-5. We successfully treated the patient with a topical calcipotriol and betamethasone ointment. CONCLUSION: We should investigate with further attention the possible impact on the human immunological ecosystem put in place by the inhibition of the activity of individual inflammatory mediators, so as to be able to recognize the initial adverse effects early.