Borrelial fasciitis: diffuse fasciitis and peripheral eosinophilia associated with Borrelia infection.

We present four cases of diffuse fasciitis (DF) associated with peripheral eosinophilia in which spirochetal organisms were identified. Two patients had borderline positive results on serologic evaluation for Borrelia burgdorferi. Deep biopsy showed dermal sclerosis associated with variable degrees of perivascular mononuclear inflammation. Diffuse fasciitis, septal panniculitis, and myositis with mononuclear cell infiltrates and varying numbers of eosinophils were observed. All cases showed a striking lymphocytic vasculopathy associated with atypical reactive endothelial cells. Using modified Dieterle and Steiner silver stains, multiple organisms were seen in one specimen, a single unequivocal organism detected in two specimens. In one case, no organisms were detected on silver stain; however, organisms were demonstrated using rabbit polyclonal antibodies against B. burgdorferi. B. burgdorferi-specific DNA was identified in one patient by the polymerase chain reaction. These results indicate that some cases of eosinophilic fasciitis are an expression of Lyme disease. We have previously proposed the more specific term "borrelial fasciitis" to describe such lesions.