Allergy and Immunology Glossary Here are definitions of some of the words frequently encountered in literature on allergy and asthma. Toggle navigation Allergies Asthma Resources News Health Care Professionals Find an Allergist Find an Allergist Symptom Test Ask the Allergist Index Allergy Anaphylaxis Antibody Antigen Antihistamine drugs An [..]

Anaphylaxis, or anaphylactic shock, is a severe, frightening and life-threatening allergic reaction. The reaction, although rare, can occur after an insect sting or as a reaction to an injected drug - for example, penicillin or antitetanus (horse) serum. Less commonly, the reaction occurs after a particular food or drug has been taken by mouth.

An antibody is a protein (also called an immunoglobulin) that is manufactured by lymphocytes (a type of white blood cell) to neutralize an antigen or foreign protein. Bacteria, viruses and other microorganisms commonly contain many antigens, as do pollens, dust mites, molds, foods, and other substances. Although many types of antibodies are protect [..]

An antigen is a substance that can trigger an immune response, resulting in production of an antibody as part of the body's defense against infection and disease. Many antigens are foreign proteins (those not found naturally in the body). An allergen is a special type of antigen which causes an IgE antibody response.

Antihistamines are a group of drugs that block the effects of histamine, a chemical released in body fluids during an allergic reaction. In rhinitis, antihistamines reduce itching, sneezing, and runny nose.

Anti-inflammatory drugs reduce the symptoms and signs of inflammation. Although not a drug, immunotherapy ("allergy shots") reduces inflammation in both allergic rhinitis and allergic asthma.

Asthma is a chronic, inflammatory lung disease characterized by recurrent breathing problems. People with asthma have acute episodes or when the air passages in their lungs get narrower, and breathing becomes more difficult. Sometimes episodes of asthma are triggered by allergens, although infection, exercise, cold air and other factors are also im [..]

Bronchitis is an inflammation of the bronchi (lung airways), resulting in persistent cough that produces consideration quantities of sputum (phlegm). Bronchitis is more common in smokers and in areas with high atmospheric pollution.

Bronchodilators are a group of drugs that widen the airways in the lungs.

Any of the larger air passages that connect the trachea (windpipe) to the lungs. The plural form of "bronchus" as "bronchi."