Low blood eosinophils: a marker of difficult-to-treat chronic spontaneous urticaria
Published online: August 28, 2019
Chronic spontaneous urticaria (CSU) is characterized by the degranulation of skin mast cells and the influx of basophils and eosinophils to affected skin sites. While blood basopenia has been linked to severe, antihistamine-resistant and autoimmune urticaria, the role of eosinophils in chronic spontaneous urticaria is largely unknown.
In the manuscript recently published in The Journal of Allergy and Clinical Immunology: In Practice, Kolkhir et al. analyzed data from 1,613 CSU patients from two centers to study the prevalence, role and relevance of eosinopenia (e.g. low blood eosinophils) in CSU. Peripheral blood eosinophil and basophil counts were measured by automated hematology analyzers. Patient files were screened for clinical characteristics, results of laboratory tests, and response to second-generation H1-antihistamines (the first and second lines of therapy) and omalizumab (the third line of therapy).
Ten percent of CSU patients had eosinopenia. Eosinopenia was associated with female gender, high disease activity, positive autoimmune markers, and poor response to treatment with second-generation antihistamines and omalizumab. The combination of eosinopenia and basopenia was a better predictor of non-response to second-generation H1-antihistamines than eosinopenia alone. Eosinophil count is a cost-effective and easy-to-assess parameter. It may help physicians to identify difficult to treat patients and to improve their management.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.