In this installment of Discourses in Dermatology, Linda Stein Gold, MD, and Jennifer Soung, MD, explore the role of IL-13 in atopic dermatitis (AD) and how targeted biologics are reshaping treatment strategies for moderate to severe disease. 

Dr. Stein Gold and Dr. Soung discuss how IL-13 drives inflammation in AD, with elevated levels present even in nonlesional skin, contributing to early disease activity, fibrotic remodeling in chronic lesions, and peripheral itch sensory neurons. They compare the mechanisms of action of dupilumab, tralokinumab, and lebrikizumab, explaining how these therapies differ in clinical practice and reviewing key phase 3 trial data on skin clearance and itch reduction. 

They also examine the long-term safety and efficacy of IL-13-targeted therapies, emphasizing that no new safety signals have emerged over time and that maintenance data through 52 and 104 weeks show sustained response in many patients. They highlight the growing shift toward higher efficacy endpoints, such as EASI90 and near-complete itch resolution, and discuss how these evolving treatment goals are raising the standard of care in AD management. 

Finally, they provide practical guidance on counseling patients about the safety and value of biologic therapy, reinforcing the importance of proactive rather than reactive disease management.