Transforming the treatment of autoimmune skin diseases: a journey through biologic therapies.

INTRODUCTION: Autoimmune blistering diseases and autoimmune connective tissue diseases with prominent skin involvement are increasingly managed with biologic and targeted therapies. We review the evidence supporting these approaches and their practical positioning. AREAS COVERED: We performed a PubMed/MEDLINE literature review (inception to February 2026) on biologic therapies for pemphigus, pemphigoid spectrum disorders, LABD, EBA, cutaneous lupus erythematosus, and dermatomyositis, including selected non-biologic small molecules, focusing on validated cutaneous outcomes. Evidence is strongest for B-cell depletion in pemphigus (including dose-optimization strategies) and for IL-4/IL-13 pathway blockade in BP, with additional data for anti-IgE therapy in selected BP phenotypes. In CLE, the most consistent cutaneous datasets involve pDC/type I interferon-axis modulation and BAFF inhibition, largely derived from systemic lupus cohorts; TYK2 inhibition has shown controlled benefit in CLE. In dermatomyositis, CDASI-based evidence is strongest for IVIg, with anti-IFNβ therapy and the TYK2/JAK1 inhibitor brepocitinib (positive in a phase 3 trial) showing cutaneous benefit; other biologics show limited trial signals. EXPERT OPINION: Biologic/targeted therapies should be positioned by disease phenotype and evidence strength, prioritizing steroid-sparing strategies in pemphigus and BP and using CLASI/CDASI-anchored outcomes to interpret lupus and dermatomyositis data. Evidence for rare AIBDs remains mostly case-level and should be framed accordingly.