Allergen: A substance that can cause an allergic reaction. Common allergens include ragweed pollen, animal dander, and mold.
- Allergic conjunctivitis
Inflammation of the whites of the eyes (conjunctivae), with itching, redness, and tearing, due to allergy.
- Allergic contact eczema
Also called allergic contact dermatitis, this is a red, itchy, weepy reaction where the skin has come into contact with a substance that the immune system recognizes as foreign, such as poison ivy or certain preservatives in creams and lotions.
- Allergic contact dermatitis
Allergic contact dermatitis: A red, itchy, weepy reaction where the skin has come into contact with a substance that the immune system recognizes as foreign, such as poison ivy, poison oak or poison sumac or certain preservatives in creams and lotions. This type of reaction reflects a specific sensitivity or allergy to a specific substance. […]
- Allergic granulomatosis
Allergic granulomatosis: A disease (also often called the Churg-Straus syndrome) characterized by inflammation of the blood vessels in persons with a history of asthma or allergy. The symptoms of the Churg-Strauss syndrome include fatigue, weight loss, inflammation of the nasal passages, symptoms of asthma, numbness, and weakness. The ultimate test for the diagnosis of Churg-Straus […]
- Allergic reaction
The hypersensitive response of the immune system of an allergic individual to a substance. When an allergen enters the body, it causes the body’s immune system to develop an allergic reaction in a person with an allergy to it. This reaction can occur when the immune system attacks a normally harmless substance (the allergen). The […]