The skin in autoimmune diseases-Unmet needs

Treatment of skin manifestations in systemic lupus erythematosus (SLE), systemic sclerosis (SSc), and dermatomyositis (DM) is based on the results of only few randomized controlled trials. The first-line treatment for disfiguring and widespread cutaneous involvement in SLE is antimalarials, but some patients are therapy resistant. Recently, the monoclonal antibody belimumab was approved for SLE as an adjunct therapy for patients with autoantibody-positive disease who despite standard therapy show high disease activity, intolerance of other treatments, or an unacceptably high need for corticosteroids. However, a validated skin score has not been used to confirm the efficacy of belimumab on mucocutaneous manifestations. In SSc, another multi-systemic progressive disease, involvement of the lung, kidney, and the heart is frequently treated with corticosteroids and immunosuppressives, but therapeutic modalities for cutaneous lesions, such as skin sclerosis and digital ulcers, are limited. In the past years, treatment with the endothelin-receptor antagonist bosentan has been proven to reduce the occurrence of new digital ulcers in SSc patients but has no or limited effect on healing of digital ulcers. DM is an idiopathic autoimmune disease characterized by inflammation of the muscles and skin, which is treated with immunosuppressives. Corticosteroids are the first-line treatment for muscle involvement in DM, but skin lesions often flare by reduction or discontinuation. In summary, there is a high unmet need for new therapeutic strategies focusing on skin involvement in systemic autoimmune diseases. Therefore, innovative designs of randomized controlled trials with validated skin scores are warranted to develop new therapeutic strategies for patients with cutaneous manifestations.