Glossary

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

Allergen: a substance that causes an allergic reaction in some people (eg, animal dander, pollen, mold spores).

Allergic reaction: a response to the presence of a substance (allergen). This substance may enter the body through skin contact, breathing it in, swallowing, or getting an injection.

Allergic rhinitis: (medical term for hay fever) an allergic reaction that mimics a chronic cold. Symptoms may include nasal congestion, a clear runny nose, sneezing, nose and eye itching, and tearing eyes.

Allergic salute: when a child continually rubs his or her nose in an upward motion, often causing a crease mark on the top of the nose.

Allergic shiner: dark circles under the eyes caused by an increase in blood flow near the sinuses.

Allergist: a doctor whose main practice is diagnosing and treating allergies.

Allergy: a hypersensitive reaction to a normally harmless substance that does not bother most people. People who have allergies often are sensitive to more than 1 substance.

Allergy scratch test: a test performed by scratching allergy-causing substances (allergens) across the skin and waiting to see if a reaction occurs.

Allergy triggers: those substances, also called allergens, that cause allergic reactions.

Antihistamine: a drug that stops the effects of histamine, a substance released during an allergic reaction. Antihistamines help reduce the sneezing and runny nose associated with nasal allergies; they are not as effective in relieving nasal congestion and may cause drowsiness.

Aspergillus: a type of mold, or fungus, that may cause several different illnesses, including both infections and allergy.

Asthma: a lung disease that typically involves difficulty breathing due to narrowed airways. Asthma attacks are sometimes triggered by an allergic reaction.

C

Congestion: the presence of an abnormal amount of fluid in the vessels or passages of a body part or organ.

Corticosteroid: anti-inflammatory medicine. In rhinitis, this type of medicine helps reduce symptoms of runny nose, sneezing, and nasal congestion.

D

Dander: tiny scales shed from human or animal skin or hair. Dander floats in the air, settles on surfaces, and makes up a good proportion of household dust. Cat and other animal dander is often a cause of allergic reactions.

Decongestant: a drug that shrinks the swollen membranes in the nose, reducing nasal congestion and making it easier for you to breathe. Decongestants may be taken orally or by nasal spray.

Dust: small particles of human or animal skin, pollen, mold, or fibers.

Dust mites: tiny organisms, commonly found in bedding, furniture, and carpeting, which feed on dust. The waste produced by dust mites can cause nasal allergy symptoms.

H

Hay fever: the common name for seasonal allergic rhinitis; symptoms are runny nose, sneezing, and nasal congestion. It is not caused by hay, and it does not produce a fever.

HEPA: High-efficiency particulate air (HEPA) filter, which removes particles in the air by forcing it through screens containing microscopic pores. HEPA filters in heating and cooling units may offer relief to those who have a high sensitivity to allergens.

Histamine: a natural substance released in the human body during an allergic reaction. Histamine is the main cause of nasal allergy symptoms.

Hypoallergenic: a term used to describe products that have been specially treated or made to resist allergens.

I

Immune system: a complex system that recognizes and protects us from any foreign substances that enter our body and also protects us from infections.

Immunotherapy: also called allergy desensitization or allergy shots; immunotherapy is given to increase your tolerance to the substances that trigger allergy symptoms. Allergy shots can reduce your sensitivity to certain substances, but they do not cure allergies. They are usually recommended for people who suffer from allergies for a major portion of the year.

Indoor allergen: allergy-causing substance found in the home such as dust mite waste, pet dander, and mold.

Inflammation: in allergic rhinitis, redness and swelling of the nasal passages.

M

Metabolism: the whole range of biochemical processes that occur within a living organism, including the buildup and the breakdown of substances that you eat or drink. Metabolism is often described or referred to as the breakdown of food and its transformation into energy.

Mold: fungi that thrive in damp, dark locations indoors and outdoors. Indoor mold is most often found in attics, basements, and bathrooms. Outdoor mold can live in leaf piles, mulch, rotting wood, and soil.

Mucus: a thick fluid produced by the lining of some organs of your body. Excess production of mucus in the nose occurs during an allergic reaction.

N

Nasal allergies: the condition of developing runny nose, sneezing, and nasal congestion in response to specific substances (allergens).

Nasal congestion: (stuffy nose) swelling of the nasal passages that results in narrowed airflow.

Nasal decongestant: an over-the-counter or prescription medicine that helps reduce swelling or nasal congestion.

Nasal steroids: medications that help reduce inflammation in the nose, providing relief from sneezing, congestion, and runny nose.

Nonallergic rhinitis: a diagnosis of nasal irritation that does not result from allergies. Some causes of this condition may be due to infection, occupation, hormones, and reactions to medications.

O

Outdoor allergen: allergy-causing substance such as pollens from trees, weeds, grasses, and molds.

P

Perennial allergic rhinitis: nasal allergies that can occur any time of year.

Pollen: the powdery particles produced by trees, grasses, flowers, and weeds that are used in reproduction. Pollen can be carried by the wind, collected on hair and clothing, and transported by shoes. Inhaling pollen often stimulates allergic reactions.

Pollen count: the number of pollen grains (per cubic meter) in the air at a particular time. The pollen count for a particular location can usually be found on the local weather forecast, in the newspaper, or online at www.pollen.com.

T

Trigger: a substance that sets off an allergic reaction; see also, allergen.