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 Inhalent Allergens

There are numerous substances commonly found in our environment which cause symptoms in allergic individuals upon exposure to them. These substances are called allergens. The allergen is an extremely small particle which usually is visible only under the microscope. Exposure to the majority of allergens occurs through inhalation, which results in allergic symptoms of the respiratory tract (nose, throat, lungs) or closely related organs (eyes or ears). An allergen which causes symptoms when inhaled is called an INHALANT ALLERGEN.

DP MITE and DF MITE - microscopic, insect-like creatures which are found in homes - the greatest source of mites is in the bedroom and upholstered furniture. It is a principal component of house dust. It is harmless, feeding off shed human skin, but has been found to be a strong allergen in susceptible individuals. Mites are a year round offender.

HOUSE DUST - is the most troublesome non-pollen inhalant allergen. House dust is not earthen dirt or soil, but is an extremely fine dust or lint-like substance. Anyone who has seen the contents of a vacuum cleaner bag knows what house dust looks like. It may sometimes be seen in the air as small particles if one looks at a bright window. It is a hodgepodge mixture of the breakdown products of various common materials found within the home. Such items as carpeting, bedding, upholstered furniture, etc. contribute to the house dust mixture as they wear out. In addition, animal sheddings, of dander and hair, feathers, household mites, insect parts and other substances are sometimes found in house dust.

TIMOTHY GRASS - found throughout the United States- pollinating period is June and July - most common and important pasture and yard grass family of the U.S.- has also become common along roadsides and fields. Has a high allergenic importance. (Other grasses in this family are: Kentucky 31, bluegrass, fescue, perennial rye, and seashore salt grass).

BERMUDA GRASS - found throughout Maryland to Oklahoma and south to Florida and Texas - pollinating period is April to September- large quantities of pollen are produced - considered to be one of the most important of hayfever grasses.

JOHNSON GRASS - found from the Mississippi eastward to the Atlantic coast, Pennsylvania and New Jersey are the northeastern limits - pollinating period is from June to October - considered a wide spread allergic factor, but because of its large size of pollen grain isn’t readily airborne - considered a secondary allergic importance.

BOX ELDER MAPLE TREE - found throughout the U.S. - pollinating period is late February through April - has a high allergic importance.

OAK TREE - inhabits the temperate regions of the Northern Hemisphere and higher altitudes within the tropics - pollinating period is late March through May - most important of hayfever producing trees.

AMERICAN ELM TREE - native to most of the U.S. east of the Rocky Mountains - pollinating period is March and April - moderate allergenic importance.

SYCAMORE TREE - found throughout the U.S., especially the eastern states - pollinating period is April and May- allergic importance is moderate.

BLACK WALNUT TREE - pollinates primarily in May and June- has a high allergenic importance.

PINE TREE - pollinates April through June - has a heavy pollen that doesn’t travel far in the air. Important only where the tree is in close proximity.

SHORT RAGWEED - found throughout the U.S. - typically found along roadsides, vacant lots and fields - pollinating period is August through November, with its peak being in Sept. and Oct., has a great allergenic importance - Ragweed accounts for over 90% of the weed pollen.

ENGLISH PLANTAIN - weed found throughout the U.S. - common lawn weed - pollinating period is April through summertime- heaviest in May and June- important cause of hayfever.

GOLDENROD - weed found throughout the U.S. - pollinating period is August and September - secondary allergic factor.

LAMB’S QUARTER - weed found throughout the U.S. - pollinating period is May to October - moderate allergenic importance.

ROUGH PIGWEED - found throughout the U.S. - pollinating period is late July through September - moderate allergenic importance.

MUGWORT - weed found throughout the U.S. - pollinates July through October - important cause of allergic symptoms.

COCKLEBUR - weed found throughout the U.S. - pollinates in August and September - significant allergenic importance.

CAT and DOG DANDER - The invisible microscopic particles of skin or “dander” are common causes of allergic symptoms. The shed hair is not the problem, thus the length of the animal’s hair, nor the amount of hair shed, is not the problem. All dogs and cats shed skin cells, thus all are potential allergic problems.

FEATHERS - or down from goose, duck, or chickens may produce reactions in allergenic individuals. Feathers shed from pet birds may also cause allergies.

COCKROACH - it is the waste product of the cockroach that causes allergy symptoms.

MOLDS or fungi are microscopic forms of plant life which grows primarily outside but may also be found inside the home. They produce tiny spores which become airborne and may be inhaled resulting in allergic symptoms. Molds are active year round (except outside during extremely cold or freezing weather). Their spore counts in the air increase during periods of“changes” in the weather in the early spring and late fall and during unusually wet or dry periods. The following are molds that are of significant importance in our area.

ALTERNARIA - considered to be one of the most common causes of symptoms due to allergy to airborne mold spores - grows on plants and plant materials.

ASPERGILLUS - common soil fungus - found on damp hay, grain, sausage and fruit.

CLADOSPORIUM - mold commonly found on decomposing plants, leather, rubber, cloth, paper, and wood products - spores are released into the air in great numbers after it rains and in damp weather - high allergenic importance.

HELMINTHOSPORIUM - mold that grows on cereal grains and plants such as corn, wheat, oats and rye - high allergenic importance.

PULLULARIA - normally found in soil but also grows on decaying vegetation, plants and caulking compounds.

PENICILLIUM - (green and blue molds) found on “food stuffs” - spores are found everywhere in the air and soil - it is the most common indoor mold. The highly purified antibiotics made today DO NOT cross react with the allergens of the spores. People with an allergy to the antibiotic Penicillin, will not be affected by testing or treatment with Penicillium mold.

MUCOR - a natural soil inhabitant- frequently found around barns and barnyards where it grows on animal waste.

EPICOCCUM - Normally a soil organism and can be found on decaying vegetative material, plant leaves, and uncooked fruit - allergenic response increases in late summer and fall.

FUSARIUM - grows on green plants such as peas, beans, cotton, tomato, corn, sweet potatoes, and rice - also found on decaying plants - high allergenic importance.

RHIZOPUS - mold that grows readily on bread, cured meats, and on root vegetables indoors - also grows on a variety of plants in nature.