A case of erythrodermic mycosis fungoides responding to upadacitinib

Abstract

Upadacitinib is a small JAK 1, 2, and 3 inhibitor, with preferential inhibition of JAK 1, approved for the treatment of rheumatoid arthritis and recently approved for the treatment of moderate-to-severe atopic dermatitis. The JAK/STAT proteins are intracellular signal transducers for several cytokines and growth factors. This pathway plays a critical role in the development and function of the immune system.1