Allergic

Allergies are a common and chronic condition that involves the body's immune system. Normally, the immune system works to fight off bacteria, viruses and other infectious agents. When you have an allergy, the immune system treats a harmless substance, like pollen or dust mite, as a threat. To fight this perceived threat, the immune system makes antibodies called immunoglobulin E (IgE).
IgE is an immunoglobulin normally present in the blood in trace amounts. Continual production of IgE antibodies in response to common naturally occurring allergens, however, often results in elevated serum levels and in the development of such clinically important Type I allergic reactions as asthma, hay fever, dermatitis and food allergies. Elevated IgE levels are also seen in parasitic (helminth) diseases, IgE myeloma, and in hepatitis. The measurement of IgE in human serum is thus considered to be useful in the diagnosis, treatment, assessment of disease progression, or postoperativeprognosis for such conditions.