
Overview
Eosinophilia is a higher than normal level of eosinophils. Eosinophils are a type of disease-fighting white blood cell. This condition most often indicates a parasitic infection, an allergic reaction or cancer. A count of more than 500 eosinophils per microliter of blood is generally considered eosinophilia in adults. A count of more than 1,500 eosinophils per microliter of blood that lasts for several months is called hypereosinophilia.1
Symptoms
Symptomatic patients — Clinical findings from the initial evaluation may inform the further evaluation of eosinophilia. Skin, lung, heart, gastrointestinal tract, and nervous system are the most commonly affected organ systems, but almost any tissue can be infiltrated by eosinophils. The following examples of findings may suggest potential causes of eosinophilia, but the prominence of a particular symptom is not sufficient to establish the diagnosis, and the absence of a finding cannot exclude certain etiologies.2
Constitutional symptoms — Symptoms of fever, sweats, unexplained weight loss, and profound fatigue are nonspecific and may be associated with numerous causes of eosinophilia. In many cases, clinical findings from other aspects of the history, physical examination, or screening laboratory studies will provide clues regarding the nature of an underlying disorder.2
Causes
Eosinophilia occurs when a large number of eosinophils are recruited to a specific site in your body or when the bone marrow produces too many eosinophils. This can be caused by a variety of factors, including:
- Parasitic and fungal diseases
- Certain types of allergies including allergies to medications or food
- Adrenal conditions
- Skin disorders
- Toxins
- Autoimmune disorders
- Endocrine disorders
- Tumors
- Specific diseases and conditions that can result in blood or tissue eosinophilia (Acute myelogenous leukemia (AML), Ascariasis (a roundworm infection), Asthma, Atopic dermatitis (eczema), Cancer, Churg-Strauss syndrome, Crohn’s disease and many others
Parasitic diseases and allergic reactions to medication are among the more common causes of eosinophilia. Hypereosinophila that causes organ damage is called hypereosinophilic syndrome. This syndrome tends to have an unknown cause or results from certain types of cancer, such as bone marrow or lymph node cancer.1