Diagnosis and classification of eosinophilic fasciitis.

Eosinophilic fasciitis (EF) is a rare scleroderma-like syndrome with an unknown etiology and pathogenesis that should be considered an immune-allergic disorder. Painful swelling with progressive induration and thickening of the skin and soft tissues of the limbs and trunk are the clinical hallmarks of the disease. Peripheral blood eosinophilia, hypergammaglobulinemia, and elevated erythrocyte sedimentation rate are the main laboratory findings. Full-thickness wedge biopsy of the clinically affected skin showing inflammation and thickening of deep fascia is essential to establish the diagnosis. The differential diagnosis includes systemic sclerosis and other scleroderma subsets such as morphea, and epidemic fasciitis syndromes caused by toxic agents such as the myalgia-eosinophilia syndrome and toxic oil syndrome. Peripheral T cell lymphomas should also be ruled out. The diagnosis of EF can be established by clinical, laboratory and histological findings, but universally accepted international diagnostic criteria are lacking. Corticosteroids are efficacious and remain the standard therapy for EF, although some patients may improve spontaneously.