Characteristics of Dermatological Patients With Blood Eosinophilia: A Retrospective Analysis of 453 Patients

Skin diseases associated with blood or tissue eosinophilia are common. Because these have various clinical manifestations, making the correct diagnosis can be challenging. So far, dermatological patients with concomitant blood eosinophilia have not been characterized. To investigate patterns of dermatological patients with concomitant blood eosinophilia to obtain information helpful for optimizing disease management. In this retrospective study, demographic and clinical data and diagnostic test results of all patients presenting with dermatoses associated with blood eosinophilia referred to a university center from 2014 to 2018 were extracted from the electronic patient charts and evaluated using descriptive and semantic map analyses. A total of 453 patients (51.4% females; mean age, 58.4 ± 21.7 years) were included and grouped according to blood absolute eosinophil counts: severe, greater than or equal to 1.5 G/L (n = 87; 19.2%); moderate, 1.0 to 1.49 G/L (n = 73; 16.1%); and mild eosinophilia, 0.5 to 0.99 G/L (n = 293; 64.7%). Most patients presented with chronic (64.6%), generalized skin lesions (75.9%), and pruritus (88.1%). Statistical analyses revealed 3 distinct patterns: (1) mild eosinophilia associated with localized skin disease, age less than 50 years, history of atopy, and diagnosis of eczema or infectious disease; (2) moderate eosinophilia linked to generalized skin lesions, pruritus, age more than 70 years, and autoimmune bullous disease; and (3) severe eosinophilia associated with diagnosis of hypereosinophilic syndromes, drug hypersensitivity, or malignant disease. Based on the pattern analysis of patients with dermatoses associated with blood eosinophilia, a diagnostic workup has been developed aiming at setting the correct differential diagnosis in a feasible and effective manner.