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 immune system calls upon a protective antibody called immunoglobulin E or IgE to fight these invading substances. Even though everyone has some IgE, an allergic person has an unusually large army of these IgE defenders -in fact, too many for their own good. This army of IgE antibodies attacks and engages the invading army of allergic substances of allergens. As is often the case in war, innocent bystanders are affected by this battle. These innocent bystanders are special cells called mast cells. When a mast cell is injured or irritated, it releases a variety of strong chemicals, including histamine, into the tissues and blood that promote allergic reactions. These chemicals are very irritating and cause itching, swelling, and fluid leaking from nearby cells. These allergic chemicals can cause muscle spasm and can lead to lung airway and throat tightening as is found in asthma and loss of voice. They are also what leads to the familiar hay fever or allergic rhinitis and common pink eye.
- Allergic rhinitis
Allergic rhinitis: Medical term for hay fever, an allergic reaction that mimics a chronic cold. Symptoms include nasal congestion, a clear runny nose, sneezing, nose and eye itching, and tearing of the eyes. Postnasal dripping of clear mucus frequently causes a cough, loss of smell is common, and occasionally loss of taste. Nosebleeds may occur. […]
- Allergic rhinitis, perennial
Allergic rhinitis, perennial: Allergic rhinitis that occurs throughout the year.
- Allergic rhinitis, seasonal
Allergic rhinitis, seasonal: Allergic rhinitis that occurs during a specific season.
- Allergic salute
Allergic salute: The characteristic gesture of a person with allergic rhinitis: rubbing his or her nose with the index finger.
- Allergic vasculitis
Allergic vasculitis: A disease (also more commonly 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 […]