By Shaista Tariq
The term allergy was coined by Austrian physician Clemens von Pirquetin in 1906. It is derived from two Greek roots meaning “altered reactivity”. Thus, someone reacting to a substance that does not adversely affect other people is experiencing an allergic response, according to the original definition.
Our immune system normally protects the body against harmful substances, such as bacteria and viruses. It also reacts to foreign substances called allergens, which are generally harmless and in most people do not cause a problem. But in a person with allergies, the immune response is oversensitive. When it recognizes an allergen, the immune system launches a response. Chemicals such as histamines are released. These chemicals cause allergy symptoms. Some allergic reactions are mild and harmless, but others are severe and potentially life-threatening (anaphylaxis).
Common Allergy Triggers
- Inhaled allergens – pollen from grass, trees or weeds
- Injected allergens – insect venom, medications, vaccines, hormones (insulin)
- Ingested allergens – foods, drugs taken by mouth
- Absorbed (contact) allergens – plant components, latex, dyes, fabric chemicals, paints, pesticides, resins, metals(e.g. nickel in jewellery), cosmetics ingredients, nail polish, hair dyes, fragrances.
Respiratory allergies are those that affect the organs and airways that help us breathe.
Common symptoms of such allergies include itchiness, watery or red eyes, coughing, sneezing and/or stuffiness in the nose.
Common allergies affecting the respiratory system
Hay fever (allergic rhinitis)
It can be seasonal, if it is caused by the pollen of grasses and flowers. Or it can be chronic (long-term), if it is triggered by things such as dust, animal dander or mould.
Food and drug allergies
Eating fish or shellfish may cause allergic reactions such as upset stomachs, or skin reactions, or it may cause severe breathing problems. Some other foods such as peanuts, milk, and eggs may also cause allergic reactions. Medications, too, can cause allergic reactions.
Bee stings can cause severe , life-threatening reactions in people who are allergic to them. Cockroaches can be a major household allergen, especially in densely populated areas.
Causes of Respiratory Allergies
Doctors don’t know for sure why some people get allergies, however, they have identified some factors that may make a person more likely to develop these conditions:
- Family history – the tendency to develop allergies may be inherited
- Exposure to air pollution or certain substances in the environment, like second hand smoke
- Having certain health conditions such as respiratory infections during childhood or being overweight
Food Allergy vs Intolerance
Food allergy is an abnormal reaction of the body’s immune system to a particular food, in which the body’s immune system reacts abnormally to specific foods. This tends to cause unpleasant and unwanted effects (symptoms).
A person who develops a headache, gets irritable or starts feeling edgy after consuming a particular food does not usually have an allergy. Someone who develops a migraine after eating over-ripe cheese may be reacting to the tyramine in it. The substance dilates blood vessels and may produce a headache, but that’s not an allergic reaction.
Chocolate, pineapple and citrus fruits —often accused of causing allergic reaction- rarely do. The phenylethylamine in chocolate may make people edgy and restless, strawberries and tomatoes are rich in histamine, and eating a large amount at once may cause some histamine-induced symptoms; but these are not true allergic reactions.
Food intolerance symptoms generally come on gradually and don’t involve an immune system reaction. People who have food intolerance may be able to eat small amounts of the offending food without trouble. One may also be able to take steps that help prevent a reaction. For example, if a person has lactose intolerance, s/he may be able to drink lactose-free milk or take lactase enzyme pills, like Lactaid, that aid digestion.
Allergy testing may be needed to find out whether the symptoms are an actual allergy or are caused by other problems. A runny nose or cough may actually be due to an infection. Skin testing is the most common method of allergy testing.
- June Engel, PhD with Isolde Prince. 1997. The Complete Allergy Book. Key Porter Books Limited
- William Briner, MD, 2007. Action Plan for Allergies. Human Kinetics
- www. drugstorepharmacy.ca
About the Author:
Shaista Tariq is an M.Sc., B.Sc. in Applied Science in Nutrition and a Registered Holistic Nutritionist.