Serodiagnosis in dermatological diseases in Borrelia burgdorferi infections

185 patients with dermatological symptoms of Borrelia burgdorferi infection (erythema migrans, lymphadenosis cutis benigna, acrodermatitis chronica atrophicans) and morphea were examined for Borrelia burgdorferi antibodies; in addition, sera from 173 patients were tested for exclusion of Borrelia infection. Commercially available immunofluorescence tests and enzyme immunoassays supplied by four different companies were evaluated. To investigate the specificity of these assays, sera of 34 patients with syphilis in different stages and sera from 98 control persons were examined. None of the assays evaluated was suitable for the diagnosis of early infection (sensitivity 4-35%). However, they are more reliable for the diagnosis of late infection (sensitivity 56-100%). The variation in specificity between the different assays was 82-100%. Crossreactions with Borrelia burgdorferi antibodies occurred frequently in patients with syphilis (3-47%). The reliability of serological assays should be improved by antigen purification and combination of screening and confirmatory assays. After treatment the decline in IgG and IgM antibodies is very slow.