An abnormally high number of eosinophils in the blood. Normally, eosinophils constitute 1 to 3% of the peripheral blood leukocytes, at a count of 350 to 650 per cubic millimeter. Eosinophilia can be categorized as mild (less than 1500 eosinophils per cubic millimeter), moderate (1500 to 5000 per cubic millimeter), or severe (more than 5000 per cubic millimeter). Eosinophilia may be primary or secondary. In primary eosinophilia, the increased production of eosinophils is due to an abnormality in a hematopoietic stem cell as, for example, in eosinophilic leukemia. In secondary eosinophilia, the increased production of eosinophils is a reactive process driven by cytokines, as is the case in allergy.

Alternative Names of Eosinophilia are: Pulmonary infiltrates with eosinophilia; Loeffler syndrome.

Complications of Eosinophilia

A rare complication of simple pulmonary eosinophilia is a severe type of pneumonia called acute idiopathic eosinophilic pneumonia.

Causes of Eosinophilia

There are a variety of disorders that can cause eosinophilia ranging from simple hay fever to life threatening tumor. Most common cause for eosinophilia are parasitic infections (such as hookworm, schistosomiasis), allergic conditions (such asthma and hay fever) and certain types of drug reactions. Few other rarer causes include:

• Lung diseases (e.g., Loeffler's Syndrome)
• Due to inflammation of blood vessels (e.g., Churg-Strauss syndrome)
• Certain malignant tumors (e.g., lymphoma)
• Due to certain types of antibody deficiencies
• Certain types of skin diseases (e.g., dermatitis herpetiformis), Etc. Eosinophilia in children is more difficult to diagnose as the range of probable causes is much wider in this case compared to adults.

Signs & Symptoms of Eosinophilia

• The symptoms of eosinophilia are those of the underlying condition. For example, eosinophilia due to asthma is marked by symptoms such as wheezing and breathlessness, whereas parasitic infections may lead to abdominal pain, diarrhoea, fever, or cough and rashes.
• Medicine reactions often give rise to skin rashes, and they often occur after taking a new drug.
• Rarer symptoms of eosinophilia can include weight loss, night sweats, lymph node enlargement, other skin rashes, and numbness and tingling due to nerve damage.

Diagnosis of Eosinophilia

Eosinophilia in the bloodstream can be diagnosed by a simple blood test. If problem exists in body tissues then diagnoses will involve examination of the relevant tissue. Your physician performs a biopsy of the relevant tissue in order to diagnose the condition. Certain times a lumber puncture is performed to examine spinal fluid if there are causes to suspect CSF eosinophilia.

Lab studies can be in the following lines:

• A complete blood count may be conducted in order to identify if problem exists
• A spinal fluid examination is carried out in order to diagnose eosinophilia due to worm infections.
• Imaging studies can be carried out via CT scan of the lungs, abdomen, pelvis, etc depending on symptoms and cause of eosinophilia.

Treatments of Eosinophilia

• Treatment tackles the underlying cause of the condition, whether it is an allergy, a medicine reaction, or a parasitic infection. These treatments are usually effective, and fairly non-toxic.
• Treatment for hypereosinophilic syndrome is oral corticosteroid therapy, usually starting with prednisolone (e.g. Deltacortril) at single daily doses of 30-60mg. If this is not effective, a chemotherapeutic agent is administered.

Prevention of Eosinophilia
This is a rare disorder. Many times, the cause cannot be found. Minimizing exposure to possible risk factors (certain medicines, some metals) may reduce risk.

When to seek Medical Advice
See your health care provider if you have symptoms that may be linked with this disorder.