The classical symptoms of
Lyme borreliosis (LB) on the skin, erythema migrans, borrelia lymphocytoma and acrodermatitis chronica atrophicans (ACA) can be diagnosed clinically. In atypical cases, however, the diagnosis of a Borrelia burgdorferi (Bb) infection is based on the isolation of this bacterium from affected tissues. In early
Lyme disease problems are arising in complicated erythema migrans which may represent reinfection, or with a failure of antibiotic treatment in some patients. The pathological changes in ACA presumably result from a chronic T-cell-mediated tissue injury with atrophy or sclerosis of connective tissue. On the other hand the presence of numerous plasma cells indicates activation of the humoral immune system where a progression into a malignant B-cell lymphoma is possible. In the recent past Bb could be cultivated from skin biopsies of a series of dermatoses of unknown origin, such as circumscribed scleroderma, dermatomyositis-like syndrome, relapsing nodular panniculitis, granuloma anulare and roseolar erythemas. New therapeutic strategies by administering antibiotics have been found to be effective in the described Bb induced dermatoses. Future studies should be focused on new standardized diagnostic procedures which make it possible to define the spectrum of dermatoses associated with a Bb infection.