IL4 and localized scleroderma: Although only four cases of dupilumab-associated morphea and localized sclerosis have been reported in the literature to date (Table 1), numerous cases of psoriasiform dermatitis mediated by the Th1 and Th17 pathways have been reported following initiation of dupilumab therapy.1, 3, 4, 5 In our case, this may be attributed to the inhibition of IL-4, which can promote overproduction of the IL-4δ2 variant.