Allergy Glossary

Allergen -- When a "normal" substance like food or grass begins to act as an antigen to produce IgE antibodies in an individual, the substance is called an "allergen." IgE antibodies are mediators in the allergic response, and the individual is said to be allergic to the specific allergen that initiates the IgE production.

Anergy Panel -- The words "anergy" and "allergy" look similar but they are quite different. The anergy panel may include skin testing to two or more of the following: mumps, Candida albicans, tetanus toxoid, diptheria, and trichophyton (a skin fungus). A positive anergy test just means the immune system is working properly. It does not indicate an allergy to the item tested.
Delayed reactions to skin testing

Antibody (Immunoglobulin) -- Antibodies (immunoglobulins) play a major role in the body's defense. When the immune system recognizes a substance it believes could be harmful to the body, it begins producing antibodies for protection.

Antigen -- A substance that causes the immune system to create an antibody. The body sees the antigen as "non-self" or threatening, and produces an antibody to fight it.

Fungi -- A classification of organisms including mold and yeast, mildew, mushrooms, and lichens. A single species is called a fungus.

HEPA -- HEPA stands for High Efficiency Particulate Arrester. HEPA filters are used in vacuum cleaners and air purifiers. A good HEPA filter will remove 99.97% of particulates 0.3 micron and smaller. For more information, see:
Air cleaners, air purifiers, or air filters

Histamine -- Allergens (substances you are allergic to) trigger the release of histamine in your body. Histamine is a natural substance which helps you stay alert. But when the body produces too much histamine, it causes fluid to be released into the skin (swelling and hives) or into the nasal passages or eyes (runny nose and eyes). It also causes contraction of smooth muscle in the airways, making it difficult to breathe. See also:
Testing positive for histamine

HVAC -- HVAC stands for Heating, Ventilation, Air Conditioning. This system is often a trap for dust and mold, and should be checked and/or cleaned regularly by a professional. For photos of this process in my own home, see:
Cleaning my furnace and air ducts

IAQ -- IAQ stands for Indoor Air Quality. The quality of the air we breathe is even more important for those with allergies. To see some of the questions an Indoor Air Specialist asks when he considers the IAQ, see:
Mold and air circulation

Palpitations -- Some decongestants or asthma inhalers can cause palpitations. Palpitations are sometimes described as a rapid, pounding heart beat or an unusual awareness of the heart beat. If you have chest pain, shortness of breath, or dizziness with the palpitations, you should seek medical help immediately. See also:
Antihistamines & rapid heart beat / palpitations

For a simple word exercise that shows the difference between "tachycardia" or rapid heart beat and "palpitations, click here.

If you need help understanding an allergy term, you can ask about it here.

While I can't respond personally, I will try to add definitions for words related to allergies to our glossary and note the addition in Allergy Nursing Newsletter.

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