Nine cases of different types of morphea and two of lichen sclerosus et atrophicus were investigated for the presence of neurologic symptoms. The Borrelia origin of morphea and lichen sclerosus et atrophicus was verified by the presence of antibodies against Borrelia burgdorferi and by the visualization of spirochetes on histologic sections by immunohistochemical methods. One patient had intrathecally synthesized IgG antibodies against B. burgdorferi that indicated intrathecal infection. A second patient had an elevated cell count and oligoclonal bands of unknown specificity in cerebrospinal fluid. In another patient a disturbance of the blood-brain barrier was detected. Seven patients had signs of peripheral neural involvement, mostly lesional dysesthesias. Our findings indicate frequent neural involvement in morphea and lichen sclerosus et atrophicus, suggesting the necessity of adequate antibiotic treatment in these diseases.