Retrospective Analysis of 397 Dermatoses Inpatients Associated with Blood Eosinophilia.

Background: Blood eosinophilia is often associated with various dermatoses, such as atopic eczema, urticaria, drug eruption, bullous pemphigoid, and hypereosinophilic syndrome (HES). Differential diagnosis is very challenging due to the similarities of clinical and pathological characteristics. Purpose: To investigate and analyze the clinical characteristics of dermatoses associated with blood eosinophilia (DABE) to further optimize disease management. Patients and Methods: We conducted a retrospective analysis on 397 DABE patients with blood absolute eosinophil count (AEC) greater than or equal to 0.5×109/L. Clinical characteristics, laboratory values, treatment course, and associated diagnoses were evaluated. All DABE patients were grouped based on the severity of eosinophilia as mild group (0.5 ≤ AEC×109/L < 1.5), moderate group (1.5 ≤ AEC×109/L < 3), and severe group (AEC×109/L ≥ 3). Results: Our study revealed three distinct patterns: (1) Mild eosinophilia associated with localized skin lesions, atopic history, mildly elevated total serum IgE level, diagnosed with eczema/dermatitis, and frequent antihistamines use. (2) Moderate eosinophilia has the characteristics of both mild group and severe group. (3) The severe eosinophilia group had a high proportion of elderly people without atopic history, but with acute onset, generalized skin lesions, and high level of lactate dehydrogenase, and the majority of them were diagnosed with systemic diseases (HES or tumor). Conclusion: We summarize the clinical rules of dermatoses associated with blood eosinophilia, hoping to facilitate the diagnosis and treatment for patients.