When an allergen such as pollen enters the body of a person with a sensitized immune system, it triggers antibody production. Histamine and other chemicals are released by body tissues as part of the immune response. This causes itching , swelling of affected tissues, mucus production, muscle spasms , and other symptoms. Many disorders are associated with, triggered, or worsened by allergies. These include eczema , asthma , and many others.
Allergies are very common.
And Tests History is important in diagnosing allergies , including whether the symptoms vary according to time of day or the season and possible exposures. Complement levels may be abnormal. Skin testing is the most common method of allergy testing. This may include intradermal, scratch, patch, or other tests. This disease may also alter the results of an eosinophil count - absolute test.