Lesional sweat interleukin-17A reflects local inflammatory activity and treatment response in plaque psoriasis

In a cohort of patients with plaque psoriasis, lesional sweat interleukin (IL)-17A was elevated compared with nonlesional skin and healthy controls, showed a modest association with disease activity and decreased following treatment. These findings suggest that sweat IL-17A may serve as a noninvasive, skin-proximal indicator of local inflammatory activity.