An allergy is an immune system reaction to an environmental substance called an allergen. Common allergies are caused by airborne or food allergens. The National Institute of Allergy and Infectious Diseases (NIAID) reports an estimated 35 million Americans have allergies to airborne substances. The American Academy of Asthma, Allergy and Immunology states 12 million Americans have food allergies. A group of common allergies is responsible for most allergy symptoms.
Pollens
Pollen allergy is one of the most common of all allergies. Pollen is a powder-like substance produced by flowering trees, plants, grasses and weeds. Because trees and plants flower seasonally, pollen allergies are typically seasonal. Seasonal pollen allergies--also called allergic rhinitis or hay fever--cause a runny or stuffy nose, sneezing, and itching in the nose, eyes and throat. Ragweed, lambs quarters, pigweed, sheep sorrel and curly dock are common seasonal weeds that produce large quantities of allergy-inducing pollens. Certain grasses may also cause allergies including Timothy, Bermuda, Johnson and Kentucky bluegrass. Elm, hickory, walnut, pecan and sycamore trees commonly cause pollen-related allergies. Pollen levels are typically highest in the morning, especially on dry windy days. Rain temporarily clears pollens from the air.
Molds
Molds are a form of fungus. They produce tiny seed grains called spores, which float in the air often prompting allergic reactions. Molds flourish in warm, moist, shady environments. They live both outdoors and indoors. Common locations for household mold include showers, bathtubs, basements, laundry rooms, air conditioners or humidifiers and trashcans. Mold spores are prevalent outdoors. They are particularly concentrated in compost piles and areas with decaying wood or vegetation.
Dust Mites and Cockroaches
Your skin is in a perpetual state of turnover; everyone sheds large numbers of dead skin cells daily. Dust mites are tiny pests that feed on sloughed skin cells. They are too small to see with the naked eye, but they live wherever people live--no matter how clean you are. Dust mites are most prevalent in bedding, mattresses, carpets and upholstered furniture. The waste products of dust mites can prompt an allergic response. Although you cannot completely rid your home of dust mites, you can significantly decrease their numbers. Cockroaches are another common indoor pest. Their waste products, saliva and body parts can be strong allergic triggers.
Cats, Dogs and Other Pets
Much to the chagrin of pet lovers who happen to have allergies, the skin cells, saliva and urine of cats and dogs can cause an allergic response. Hamsters, gerbils, guinea pigs and pet birds can also trigger allergies.
Foods
NIAID reports 6 to 8 percent of children younger than age 3 and 4 percent of adults have food allergies. Cow's milk, peanuts and other tree nuts, eggs, wheat, fish and shellfish, and soy are common causes of food allergies. Typical symptoms include nasal stuffiness, sneezing, itchy or watery eyes, skin rashes, hives, vomiting, diarrhea and abdominal cramps. Food allergies can cause a severe and potentially life-threatening reaction called anaphylaxis. Wheezing, hoarseness, and tightness in the chest or throat are typical symptoms of anaphylaxis. If you experience any of these symptoms, seek emergency medical care.
References
- American Academy of Otolaryngology: Allergies and Hay Fever
- National Institute of Environmental Health Sciences: Cockroaches Allergy
- National Institute of Environmental Health Sciences: Dust Mites Allergy
- National Institute of Environmental Health Sciences: Mold Allergy
- National Institute of Environmental Health Sciences: Pets and Animal Allergy
