esinophiliaEosinophilia is the state of having a high concentration of eosinophils (eosinophil granulocytes) in the blood. The normal concentration is between 0 and 0.5 x 109 eosinophils per litre of blood. Eosinophilia can be reactive (in response to other stimuli such as allergy or infection) or non reactive.

The release of interleukin 5 by T cells, mast cells and macrophages stimulates the production of eosinophils.

Diseases that feature eosinophilia:

Allergic disorders
Asthma
Hay fever
Drug allergies
Allergic skin diseases

Pemphigus

Dermatitis herpetiformis
Parasitic infections
Some forms of malignancy
Hodgkin’s lymphoma
Some forms of Non-Hodgkin lymphoma
Systemic autoimmune diseasess
Some forms of vasculitis
Cholesterol embolism (transiently)
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.
Hypereosinophilic syndrome
Hypereosinophilic syndrome is a condition where there is no apparent cause for eosinophilia.
This rare condition can affect the heart, resulting in heart failure with breathlessness and ankle swelling, cause enlargement of the liver and spleen, resulting in swelling of the abdomen, and give rise to skin rashes.

Eosinophilia-myalgia syndrome (EMS) is an incurable and sometimes fatal flu-like neurological condition that is believed to have been caused by ingestion of poorly produced L-tryptophan supplements. Similar to regular eosinophilia, it causes an increase in eosinophil granulocytes in the patient’s blood