Two patients with clinical and pathologic features of eosinophilic fasciitis manifested serologic and systemic abnormalities that raised the question of the fundamental nature and relationship of eosinophilic fasciitis to scleroderma. In addition to the characteristic features of eosinophilic fasciitis, both patients exhibited arthritis, a predominantly mononuclear cell infiltration of muscles with normal serum muscle enzyme levels, weakly positive serum antinuclear factor, IgA deficiency, and abnormalities of pulmonary function. In addition, one patient had wide-mouthed colonic diverticulae and synovial deposits consistent with amyloid; the second patient had bone marrow hypoplasia. Although corticosteroid therapy was of benefit, hydroxychloroquine and potassium para-aminobenzoate were of further help in controlling the disorder. Biopsies from the two patients revealed inflammatory lesions to be heaviest deep in the skeletal muscle; fascia was only minimally inflamed with mild fibrosis. The findings suggest that striking fibroinflammatory lesions noted in the fascia in some patients with eosinophilic fasciitis may derive largely from spillover of lesions in neighboring skeletal muscle. Shulman recently described a scleroderma-like disease characterized clinically by thickening of the skin and pain and swelling of the distal extremities, often with rapid development of contractures (1,2). Unlike scleroderma, however, the onset was relatively rapid and followed episodes of unusual physical exertion. Furthermore, there was striking peripheral blood eosinophilia. Raynaud's phenomenon, telangiectasia, myositis, and extracutaneous manifestations were absent, as were various serologic markers including antinuclear antibodies and antibodies to the extractable nuclear antigen. Most importantly, the disease usually responded well to steroid therapy. Pathologically, the syndrome apparently differed from scleroderma in that the fibroinflammatory lesions showed a predilection for fascia, as opposed to subcutis and dermis. Patients with similar features were soon thereafter reported by others, and it was suggested that this was a clinicopathologically distinct connective tissue disease for which the name "Eosinophilic fasciitis" was proposed (3).As clinical and pathologic experience with this syndrome accumulated, the distinction between scleroderma and eosinophilic fasciitis became somewhat blurred. Much discussion has ensued as to the exact features which define this entity and differentiate it from scleroderma (43). We have recently seen two patients whose clinical and pathologic features warrant classification of their disease process as eosinophilic fasciitis. Clinical scrutiny and correlative pathologic examination, including ultrastructural study, provide some insights into the relationship of eosinophilic fasciitis and scleroderma. This report addresses the clinical, immunologic, and histologic aspects. The immunohistochemical and ultrastructural findings and the pathogenesis are discussed in detail in a separate rep...
