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Causes of high and low eosinophils
Medical expert of the article
Last reviewed: 04.07.2025
Eosinophilia is an increase in the number of eosinophils in the blood (more than 0.4×10 9 /l in adults and 0.7×10 9 /l in children). In some conditions (fibroplastic parietal endocarditis of Loeffler, nodular polyarteritis, lymphogranulomatosis), hypereosinophilic leukemoid reactions with eosinophilic hyperplasia of the red bone marrow and tissue eosinophil infiltration are possible. Parasitic invasions and atopic diseases are most often accompanied by eosinophilia.
Invasion by helminthic parasites is the cause of prolonged eosinophilia; less often, eosinophilia is caused by protozoa. In case of invasion by intestinal parasites, eosinophilia is rarely pronounced. However, an increase in the eosinophil content to 10-30% and even up to 69% is possible with strongyloidiasis. In allergic conditions, eosinophilia is usually moderate - from 0.2 to 1.5×10 9 /l, but in some cases it can be higher, for example, with bronchial asthma or angioedema. Pronounced and stable eosinophilia (from 10 to 60%) is observed with pemphigus and Duhring's dermatitis herpetiformis. In addition, eosinophilia accompanies nodular polyarteritis (in 18% of patients the eosinophil content reaches 84%), rheumatoid arthritis complicated by vasculitis and pleurisy. Hypereosinophilic syndrome is also encountered, in which leukocytosis reaches 138×10 9 /l, with eosinophils accounting for 93%.
The main causes leading to eosinophilia.
Main diseases and conditions accompanied by eosinophilia and causes |
Clinical forms |
Allergic diseases Parasite infestations Tumors Immunodeficiencies Connective tissue diseases |
Bronchial asthma, hay fever, allergic dermatitis, drug allergy Ascariasis, toxocariasis, trichinosis, echinococcosis, schistosomiasis, filariasis, strongyloidiasis, opisthorchiasis, hookworm disease, giardiasis Hemoblastoses (acute leukemia, chronic myelogenous leukemia, erythremia, lymphomas, lymphogranulomatosis), other tumors, especially with metastases or necrosis Wiskott-Aldrich syndrome Polyarteritis nodosa, rheumatoid arthritis |
Eosinopenia - a decrease in the eosinophil content (less than 0.05×10 9 /l) - in most cases is caused by an increase in adrenocorticoid activity, which leads to a delay in eosinophils in the bone marrow. Eosinopenia is especially characteristic of the initial phase of the infectious-toxic process. A decrease in the number of eosinophils in the postoperative period indicates a serious condition of the patient.