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Understanding Allergies -- the Basics

Types of Allergies continued...

Respiratory allergies: Approximately 20 million Americans suffer from hay fever (allergic rhinitis), which frequently also causes bouts of sinusitis. Typical symptoms include itchy eyes, nose, roof of mouth, or throat, along with nasal congestion, coughing, and sneezing. If you (or members of your family) have other allergic conditions such as eczema or asthma, you are more likely to suffer from hay fever. Hay fever can be caused by a number of different substances -- pollens of ragweed, grasses, and other plants whose pollen is spread by the wind, as well as molds, dust, and animal dander (dead skin scales and saliva). Mold allergies are caused by spores in the air. Outdoor molds thrive in warm seasons or climates, while indoor molds grow year round in damp locations (basements and bathrooms, for example). Dust causes allergies because it harbors offenders such as pollen, mold spores, and microscopic dust mites; it may also contain irritating fibers from fabrics, upholstery, and carpets.

Asthma : Asthma has various causes and factors that trigger it, including respiratory viruses, environmental exposures, and allergies to pollen, mold spores, animal dander, and dust mites.

Food allergies : True food allergies caused by IgE and histamine are rare in adults but are more common in infants and young children. It is sometimes difficult to pinpoint the specific substances responsible for a food allergy because reactions are often delayed or may be caused by food additives or even by eating habits. However, approximately 90% of food allergies in children are caused by proteins in cow's milk, egg whites, peanuts, wheat, or soybeans. Other potential food allergens include berries, shellfish, corn, beans, yellow food dye No. 5 (tartrazine), and gum arabic (an additive in processed foods). The classic symptoms of food allergy include stomach cramps, diarrhea, and nausea. In more severe cases, there may be vomiting, swelling of the face and tongue, and respiratory congestion as well as dizziness, sweating, and faintness.

Drug allergies: The most common drug allergy is to antibiotics in the penicillin family. Allergies have been seen to most types of antibiotics -- especially sulfa drugs. Sulfa is also found in drugs other than antibiotics, such as in the arthritis drug Celebrex. Allergies have also been seen with many other types of drugs as well. Nearly 1 million Americans (and up to 10% percent of people with asthma) have reactions to aspirin. While some of these responses are IgE- or histamine-related allergies, especially if associated with asthma and nasal polyps, most are not true allergies but rather "sensitivities” or “intolerances.”

Insect sting allergies : Some studies speculate that people who have other allergies (food, drug, or respiratory) may be more susceptible to insect sting allergies, which affect about 15% of the population. Venoms in stings of bees, wasps, hornets, yellow jackets, and fire ants are common allergens.

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