Evaluation and Differential Diagnosis of Hypereosinophilia in Rheumatology Practice.

Üsküdar Cansu D., Üsküdar Teke H., Yıldırım R., Dinler M., Korkmaz C.

International archives of allergy and immunology, vol.183, no.1, pp.51-58, 2022 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 183 Issue: 1
  • Publication Date: 2022
  • Doi Number: 10.1159/000518148
  • Journal Name: International archives of allergy and immunology
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Agricultural & Environmental Science Database, BIOSIS, CAB Abstracts, EMBASE, Food Science & Technology Abstracts, MEDLINE, Veterinary Science Database
  • Page Numbers: pp.51-58
  • Keywords: Eosinophilia, Hypereosinophilia, Rheumatology, Eosinophilic granulomatosis with polyangiitis, EOSINOPHILIA
  • Eskisehir Osmangazi University Affiliated: Yes


Background: There has been no investigation so far on the prevalence or causes of hypereosinophilia during rheumatic diseases. Objectives: The study aimed to identify the prevalence and causes of hypereosinophilia among the patients followed in a rheumatology department. Methods: The patients aged 18 years or over followed in our rheumatology department between January 2010 and December 2019 who had at least one AEC >= 1,500/mu L measurement in their peripheral blood count were identified retrospectively. Results: Over the 10 years, a total of 130,769 peripheral blood counts were performed, of which 3.9% showed eosinophilia and 0.065% showed hypereosinophilia. Hypereosinophilia was identified in 85 patients. The underlying rheumatic disease was determined in 89.4% (n = 76) of patients. Of these, the most frequent one was rheumatoid arthritis at a ratio of 40.8%, followed by eosinophilic granulomatosis with polyangiitis (EGPA) at a ratio of 10.5%. Hypereosinophilia was in primary form in 3.5% of the patients, whereas secondary to another condition in 91.8% (n = 78) of the cases and idiopathic in 4.7% (n = 4) of patients. The most common cause of secondary hypereosinophilia was drug induced, as detected in 61.2%, followed by allergic conditions in 11.5% and EGPA in 9.4%. In 15.2% (n = 13) of the cases, hypereosinophilia was associated with an underlying rheumatic disease. In the cases with drug-induced hypereosinophilia, most often (in 28.8%) methotrexate was the offending agent. Conclusions: Rheumatologists should be cognizant that hypereosinophilia concurrent to rheumatic diseases is usually not due to the underlying rheumatic disease, except for the conventional eosinophil-related rheumatic diseases.