The role of intravenous immunoglobulin in autoimmune diseases with dermatological implications.

Intravenous immunoglobulin (IVIG) therapy has emerged as a promising treatment option for various dermatological autoimmune diseases due to its immunomodulatory potential and low incidence of severe side effects. Despite its widespread use, the mechanism of action of IVIG in treating autoimmune diseases remains a topic of debate. IVIG is derived from the plasma fractionation of a large pool of donors, primarily consisting of the IgG isotype. Its main mechanisms of action involve neutralizing circulating autoantibodies via the F(ab')2 portion, inhibiting complement-mediated tissue destruction, and reducing the half-life of circulating autoantibodies through the Fc portion. This paper explores the growing utilization of IVIG as an off-label therapy in dermatological autoimmune or immune-mediated diseases, including autoimmune bullous disease (AIBS), dermatomyositis (DM), lupus erythematosus (LE), systemic sclerosis, scleromyxedema, Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), pyoderma gangrenosum (PG), and necrobiotic xanthogranuloma (NXG). In this context, the sole large prospective, randomized trial was the 2022 ProDERM study, which demonstrate efficacy of IVIG in improving cutaneous manifestations among 95 DM patients compared to the placebo group. Moreover, although considered off-label, the use of IVIG is regarded as the first-line therapy for patients with scleromyxedema. As a first line of therapy, IVIg is only approved for Kawasaki Disease (KD) in the setting of vasculitis. The treatment in all other indications is mostly considered as adjuvant therapy only after failure of immunosuppressive therapy or in the presence of contraindications.