[Management of severe skin disorders in sarcoidosis].

Sarcoidosis is a systemic granulomatous condition of unknown origin. It is defined by histological features of epithelioid and giant-cell granuloma without caseous necrosis. Skin manifestations are observed in 25% of the cases of sarcoidosis, sometimes appearing as the inaugural symptom. Although these skin disorders are not life threatening, they do have a major functional and/or esthetic impact and may require specific therapy using aggressive treatments. Recent progress in immunology and molecular biology is helpful in understanding interactions between monocyte-macrophages and T lymphocytes and the cytokine pattern implicated in the granulomatous reaction. Research concerning the agent(s) causing the focus of the immune response on the TH1 pathway may be helpful in developing promising immunomodulation therapies. The very unpredictable course of the disease explains the difficulties encountered in assessing therapeutic efficacy and the small number of controlled trials. General corticosteroid therapy remains the mainstay treatment for severe skin disorders in sarcoidosis. APS and local corticoid therapy can be useful when systemic corticosteroids are not needed or to achieve a steroid-sparing effect. Indications for methotrexate and new compounds such as thalidomide or certain antibiotics with an immunomodulator effect remain to be evaluated.