Association Between Peripheral Eosinophilia and Clinical Characteristics of Adult-onset Still's Disease with Persistent Eruption: A Retrospective Study.

Persistent eruption occurs in a subset of patients with adult-onset Still's disease. In our experience, a considerable proportion of these patients present with peripheral eosinophilia. The aims of this study were to summarize the clinical and histological features of patients with adult-onset Still's disease with persistent eruption in the current study cohort, and to assess the association between peripheral eosinophil levels and disease characteristics. A total of 21 patients with adult-onset Still's disease with persistent eruption were included in this retrospective study. Koebner signs, an important diagnostic clue, were found in 85.7% of patients. The proportion of patients presenting with eosinophilia within the disease course was 57.1%. Skin histology revealed infiltration of eosinophils in 90.5% of patients. Peripheral eosinophil levels were positively associated with involved body surface area. Patients with normal peripheral eosinophil counts were more likely to achieve complete remission than those with abnormal peripheral eosinophil counts. Eosinophils may be involved in the pathogenesis of skin eruption. Abnormal peripheral eosinophil counts in these patients may indicate a more refractory disease course.