[Immunosuppressive therapy after transplantation. Dermatologic relevance and pathomechanisms].

Immunosuppressive therapy keeps rejection in check following solid organ transplantation. Drug reactions, inflammatory and infectious skin conditions frequently follow. Specific side effects can be avoided by switching individual agents. In addition to UV light, immunosuppressants are the most important driver for squamous cell carcinoma of the skin (SCC). Beyond immunosuppression, cyclosporine A promotes carcinogenesis by TGF beta and VEGF, while mTOR inhibitors are antiproliferative. Azathioprine photosensitizes to UVA and enables UVA to damage DNA directly. To fight skin cancer, global reduction of immunosuppression is the most effective measure. Switching calcineurin inhibitors to mTOR inhibitors is probably to be recommended, while omitting azathioprine may potentially be advisable in recurrent SCC.