Targeted dual biologic therapy for erythroderma of unknown etiology guided by high-parameter peripheral blood immunophenotyping.

Erythroderma is a severe and heterogeneous inflammatory skin condition with little guidance on the approach to management in cases of unknown etiology. To guide therapeutic selection, we sought to create an immunophenotyping platform able to identify aberrant cell populations and cytokines in subtypes of erythroderma. We performed high-parameter flow cytometry on peripheral blood mononuclear cells (PBMCs) and whole blood of a patient with refractory idiopathic erythroderma, erythrodermic patients with Sézary syndrome and pityriasis rubra pilaris, and healthy controls.