Methods: The patients whose blood samples showed an eosinophil count of ≥2000/μL, among the samples tested for blood cell counts and differential counts between Jan. 2006 and Oct. 2010, in Japanese Red Cross Medical Center, were firstly included Among these, patients with AE were extracted. The AE diagnosis was based on angioedema developing concurrently with eosinophilia and improving with the recovery from eosinophilia.
Results: All of the 11 patients were Japanese young females. One patient with clear arthralgia showed radioisotope accumulation in the joints by bone scintigraphy, and was diagnosed as having arthritis. The peak peripheral blood eosinophil count was 7,839±6,008 (2,130-23,170)/μL after visiting our hospital. An increase in white blood cell count was only due to an increase in eosinophil count. Serum C-reactive protein and Immunoglobulin E levels remained almost normal. Peripheral blood eosinophil count decreased steadily for 8 weeks after the first visit, regardless of steroid use. Edema in all of the patients and arthralgia in 6 patients improved within 12 weeks. None of the patients had a recurrence of AE.
Conclusions: AE developed in Japanese young females and likely showed a single course. In AE, the count of eosinophil of 104/μL was observed. Only eosinophil count increased without changes in changes in the counts of other leukocyte series. Serum C-reactive protein and Immunoglobulin E levels remained almost normal. The eosinophil count in AE patients will return to the normal level within 8 weeks even without steroid therapy.