Frequency, levels, and significance of blood eosinophilia in systemic sclerosis, localized scleroderma, and eosinophilic fasciitis.

Blood eosinophilia is a common feature of eosinophilic fasciitis and is variably reported in systemic sclerosis and localized scleroderma. Since these diseases share cutaneous fibrosis as the final outcome and have other clinical and pathologic features that are difficult to differentiate, the presence of blood eosinophilia may be a further source of confusion. In this study, we examined the frequency and level of blood eosinophilia in 715 patients with systemic sclerosis, 72 patients with localized scleroderma, and 22 patients with clinically active eosinophilic fasciitis. When defined as greater than 400 cells/mm3, eosinophilia was present in 7% of patients with systemic sclerosis, 31% of patients with localized scleroderma, and 83% of patients with eosinophilic fasciitis. Greater than 1000 eosinophils/mm3 were present less frequently in systemic sclerosis (1%) and localized scleroderma (8%) than in eosinophilic fasciitis (61%). No difference in the frequency of eosinophilia was present in patients with the limited cutaneous CREST syndrome or the diffuse cutaneous variety of systemic sclerosis, and in these patients the presence of eosinophilia did not correlate with the extent of cutaneous or internal organ involvement or with other laboratory abnormalities. Among patients with localized scleroderma, eosinophilia was more common in those with linear scleroderma and generalized morphea than in those with morphea, and both the frequency and level of eosinophilia were greater in individuals with clinically active disease (p less than 0.02). Eosinophilia was a persistent feature in untreated patients with active eosinophilic fasciitis, even up to 30 months of disease duration.