Paradoxical reversed plantar involvement during ixekizumab therapy for psoriasis

Palmoplantar psoriasis is a particularly challenging variant of psoriasis. Psoriasis at this location has a significant impact on health-related quality of life and is often recalcitrant. However, difficult cases may respond to biologic therapies. Paradoxical reactions during treatment with biological agents have been described, mostly during anti-tumor necrosis factor therapy. These typically present as a change in morphology or distribution of lesions. We present a patient with palmoplantar psoriasis treated with ixekizumab who achieved a favorable response that was coupled with a rare paradoxical reaction, reversed plantar involvement. The reason for this phenomenon and its clinical course are uncertain, but these new lesions are proving recalcitrant to complementary therapies. Provided the increasingly widespread use of biologic therapies, the incidence and diversity of paradoxical reactions are expected to increase.