Unilateral eosinophilic fasciitis: a case report and review of the literature.

A 59-year-old Japanese man developed pruritus and swelling of the right dorsal foot after weeding his garden in a crouching position for approximately one hour. Over a period of five months, the swelling, as well as skin induration, progressed unilaterally from the right thigh to the lower leg and dorsal foot. Laboratory tests, including eosinophil fraction and inflammatory markers, were within normal limits, and computed tomography showed no evidence of deep vein thrombosis or malignancy. A full-thickness biopsy including the fascia revealed marked fascial thickening with fibrosis of the subcutaneous connective tissue, and perivascular lymphocytic inflammatory infiltrates without conspicuous eosinophils, leading to a diagnosis of eosinophilic fasciitis. Oral prednisolone (30 mg/day) resulted in gradual improvement. To the best of our knowledge, 11 cases of unilateral eosinophilic fasciitis have been reported (three in Japan and eight outside Japan). Including the present case (total 12), six cases lacked peripheral blood eosinophilia, and seven lacked significant eosinophilic infiltration in tissue; five showed neither. Eosinophilic fasciitis should be considered even in the absence of eosinophilia; therefore, early full-thickness biopsy including the fascia is essential for accurate diagnosis.