[In vivo and in vitro detection of borrelia infection in morphea-like skin changes with negative Borrelia serology].

No decision has been made yet as to whether or not the origin of the circumscribed scleroderma (morphea) is spirochetal. We describe a morphea-like skin lesion that developed after a tick bite 10 years ago. The histological investigation showed sclerodermal characteristics and necrobiosis lipoidica of the granulomatous type as well. No antibodies directed against Borrelia burgdorferi could be detected absorbance by a flagellin ELISA or by Western blot analysis. The VDRL, TPHA and FTA absorbance test, Warthin-Starry staining, and cultivation of Borrelia from skin biopsies were negative. The application of a nested polymerase chain reaction (PCR), relying on a combination of flagellin-gene-specific primers, demonstrated for the first time the presence of Borrelia DNA in a morphealike skin lesion. Immunohistological examination of the skin by a monoclonal antibody directed against flagellin was positive. Furthermore, in vitro GM-CSF secretion and lymphocyte proliferation upon stimulation with Borrelia-antigen was elevated and decreased significantly after 3 weeks of treatment with tetracyclines. In this case PCR analysis, immunohistochemistry and cellular immune response confirmed an infection with Borrelia, although no serum antibodies against spirochetal antigens could be detected.