Pollen Allergy
Cat Dander
Dog Dander
Dust Mite
Mold / Fungus
Environmental Control

Pollen Allergy

Each spring, summer, and fall, tiny particles are released from trees, weeds, and grasses. These particles, known as pollen, hitch rides on currents of air. Although their mission is to fertilize parts of other plants, many never reach their targets. Instead, they enter human noses and throats, triggering a type of seasonal allergic rhinitis called pollen allergy, which many people know as hay fever or rose fever (depending on the season in which the symptoms occur). Of all the things that can cause an allergy, pollen is one of the most widespread. Many of the foods, drugs, or animals that cause allergies can be avoided to a great extent; even insects and household dust are escapable. Short of staying indoors when the pollen count is high--and even that may not help--there is no easy way to evade windborne pollen.

People with pollen allergies often develop sensitivities to other troublemakers that are present all year, such as dust mites. For these allergy sufferers, the "sneezin' season" has no limit. Year-round airborne allergens cause perennial allergic rhinitis, as distinguished from seasonal allergic rhinitis.

What is pollen?

Plants produce microscopic round or oval pollen grains to reproduce. In some species, the plant uses the pollen from its own flowers to fertilize itself. Other types must be cross-pollinated; that is, in order for fertilization to take place and seeds to form, pollen must be transferred from the flower of one plant to that of another plant of the same species. Insects do this job for certain flowering plants, while other plants rely on wind transport.

The types of pollen that most commonly cause allergic reactions are produced by the plain-looking plants (trees, grasses, and weeds) that do not have showy flowers. These plants manufacture small, light, dry pollen granules that are custom-made for wind transport. Samples of ragweed pollen have been collected 400 miles out at sea and 2 miles high in the air. Because airborne pollen is carried for long distances, it does little good to rid an area of an offending plant--the pollen can drift in from many miles away. In addition, most allergenic pollen comes from plants that produce it in huge quantities. A single ragweed plant can generate a million grains of pollen a day.

The chemical makeup of pollen is the basic factor that determines whether it is likely to cause hay fever. For example, pine tree pollen is produced in large amounts by a common tree, which would make it a good candidate for causing allergy. The chemical composition of pine pollen, however, appears to make it less allergenic than other types. Because pine pollen is heavy, it tends to fall straight down and does not scatter. Therefore, it rarely reaches human noses.

Among North American plants, weeds are the most prolific producers of allergenic pollen. Ragweed is the major culprit, but others of importance are sagebrush, redroot pigweed, lamb's quarters, Russian thistle (tumbleweed), and English plantain.

Grasses and trees, too, are important sources of allergenic pollens. Although more than 1,000 species of grass grow in North America, only a few produce highly allergenic pollen. These include timothy grass, Kentucky bluegrass, Johnson grass, Bermuda grass, redtop grass, orchard grass, and sweet vernal grass. Trees that produce allergenic pollen include oak, ash, elm, hickory, pecan, box elder, and mountain cedar.

It is common to hear people say that they are allergic to colorful or scented flowers like roses. In fact, only florists, gardeners, and others who have prolonged, close contact with flowers are likely to become sensitized to pollen from these plants. Most people have little contact with the large, heavy, waxy pollen grains of many flowering plants because this type of pollen is not carried by wind but by insects such as butterflies and bees.

When do plants make pollen?

One of the most obvious features of pollen allergy is its seasonal nature--people experience it symptoms only when the pollen grains to which they are allergic are in the air. Each plant has a pollinating period that is more or less the same from year to year. Exactly when a plant starts to pollinate seems to depend on the relative length of night and day--and therefore on geographical location--rather than on the weather. (On the other hand, weather conditions during pollination can affect the amount of pollen produced and distributed in a specific year.) Thus, the farther north you go, the later the pollinating period and the later the allergy season.

A pollen count, which is familiar to many people from local weather reports, is a measure of how much pollen is in the air. This count represents the concentration of all the pollen (or of one particular type, like ragweed) in the air in a certain area at a specific time. It is expressed in grains of pollen per square meter of air collected over 24 hours. Pollen counts tend to be highest early in the morning on warm, dry, breezy days and lowest during chilly, wet periods. Although a pollen count is an approximate and fluctuating measure, it is useful as a general guide for when it is advisable to stay indoors and avoid contact with the pollen.

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Cat Allergy

Approximately two percent of the United States population is allergic to cats. One third of these ignore medical advice and keep at least one cat in their home.

What Is A Cat Allergy?

A glycoprotein, Fel d-I, secreted by the subaceous glands, is the major cat allergen. This allergen is found in the fur, pelt, saliva, serum, urine, mucous, salivary glands, and hair roots of the cat. The main sources of the allergen, however, are the skin and saliva.

Cat allergen is so small it can remain airborne for months. It is about 10 times smaller than pollen or dust particles. According to research, it can be found in the dust of almost one third of homes that do not own a cat. It can be carried in on clothing or already be present from a previous cat owner. Studies have shown that moderate to high levels of cat allergen can even be found in schools, hospitals, and doctor's offices.

Symptoms

Cat allergy can play havoc with the eyes, nose, ears, throat, lungs, and skin. The eyes may become red, itchy, watery, or swollen. The nose may itch, run, sneeze, or become congested. The ears may become plugged or itchy. The throat may have post-nasal drip, frequent throat clearing, itching and hoarseness. The lung symptoms may include coughing, wheezing, chest tightness, shortness of breath, and frequent bronchitis. The skin may develop itchy rashes or hives.

Are There Any Hypoallergenic Cats?

There are no hypoallergenic cats. Male cats produce substantially more of the Fel d-I protein than female cats. Also neutered males produce less than non-neutered males. These factors, however, do not guarantee a female or a neutered cat will be safe for an allergic individual.

Preventative Measures

Two major factors that affect airborne cat allergen in the home are the quantity of soft furnishings and whether a cat is kept indoors or outdoors.

The "ideal" way to reduce cat allergen in the home is to remove the cat from the home. Once the pet is removed, then all floors should be vacuumed or mopped thoroughly, walls wiped down with a damp cloth, and rooms aired out regularly to reduce the level of cat allergen. A special filter should be used on the vacuum cleaner to prevent redepositing the allergen into the air. Remember to replace the heating/air system filters during this process. Keep in mind it may take up to 6 months to reduce the allergen in your home.

If removing the cat is not an option, there are ways to reduce the allergen. First, vinyl or hardwood floors are recommended instead of carpet. The use of soft upholstered furniture and draperies should be minimal. Limit the cat to certain parts of the house. The bedroom and living room should be off limits. Research shows a significant reduction in allergen levels if a cat is washed weekly.

Treatment for Cat Allergy

As with any allergy, avoidance is the main course of treatment. A cat allergic individual should avoid being around cats at all times. However, since many cat allergic people ignore the advice of their physician, there are ways to help reduce the reactions. Over the counter medications, prescription medications, and allergy shots are all ways to treat cat allergy.

Below is more information on Cat Allergy

That 10 to 25% of atopic persons are sensitive to cat dander has been long appreciated. Cat dander allergy, and especially allergic asthma, seem to be more common with cat dander than with dog dander. This may be less a question of inherent potency than an issue of greater indoor presence and possibly less washing as well. In homes, cat allergen peaks in winter and early spring: Fel d 1 levels are 2.4 times higher than in summer. Cat allergen is ubiquitous in public places, especially in seats or chairs shared by many people. Within 3 weeks, showroom mattresses achieve levels found in homes with former cats just because of contact with random customers.

The major cat allergen was first purified by Ohman et al.Originally thought to be primarily a salivary protein that was distributed across the pelt by the cat's propensity for licking, Bartholomé et al6 demonstrated that the major cat allergen, although found in mucous salivary glands, was also produced in hair root sebaceous glands. Immunohistochemical studies supported Fel d 1 production in the sebaceous gland cells and to a lesser degree by basal squamous epithelial cells, with storage on the surface of the epidermis and fur.Fel d 1 is found in particularly high concentrations in the anal sebaceous glands, and homology with steroid-binding proteins suggests a lipid regulatory role on the skin and fur.8 Fel d 1 is shared by all domesticated cats; similar cross-reacting proteins having been found in large (jungle) cats as well.

Viander et al performed RAST inhibition studies on cat hair and dog dander, saliva, and urine. They found some cross-reactivity between the dander components, but saliva and urine seemed to be species-specific. Although Fel d 1 is not found in other Figures mammals, there does seem to be some epitope sharing between major allergens of dog and cat based on immunoblot inhibition (with unique allergens as well). The minor allergen, cat albumin, shares cross-reactivity with albumins of other animals, such as dog albumin. Patients with selective cat sensitivity are most likely to be reactive to Fel d 1, whereas a number of patients sensitive to both cats and dogs will be sensitive to albumin.

There are flakes and scales of epidermis on the hair shafts that are laden with allergen. Approximately one-quarter of the airborne allergen load will be contained on particles <2.5 µm.Because these are fully respirable particles, this may explain the propensity for cat exposure to induce lower respiratory symptoms.

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Dog Allergy

WHO wants to be allergic to Man's best friend? No one, because dogs are great companions, loyal, and they ask little in return - unless it's your position on the bed! Some dogs are always trying to change the pecking order! The major allergen, or trigger, is a protein from the dog pelt. The reason a person becomes sensitized to these allergens is unknown, but appears to be related to continued exposure.

Do you get a runny nose and/or watery eyes or a skin reaction such as a rash or develop an Asthma attack? Then you may be suffering from allergy to dogs! Do you know that airborne particles shed from dogs? As with cats, once symptoms to dogs have emerged they tend to persist for a long time.

This practical information is made available by the Allergy Centre. An Allergist can tell you if you have Dog Allergy, what it is, why you have it, how you can be tested for it, what you can do about it, the best treatment, whether you should be desensitised, the best medication to use, the best place to seek treatment and whether you can get a cure for Dog Allergy.

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Dust Mites

Dust Mites are related to ticks and spiders, and are part of the house dust. One gram of dust can house up to 500 mites. An ounce can host some 13,500. A double bed mattress can easily hold 2 million mites. A 6 year-old pillow can get one-tenth of its weight from mites, dead mites and mite droppings. The dust mite feeds on dead skin scales that people shed every day. The dust mite will eat an average of 50 million skin scales that people shed every day. The average mattress can gain five pounds a year from human body ash. It is God's way to clean up after us. The average mite produces about 20 highly allergic fecal pellets per day, which is enough to equal their weight in just a few days. The fecal matter is very light and can stay air born for hours. The dust mites have sticky feet that cling to surfaces making it impossible to remove them by vacuuming the carpets or mattress.

Vacuuming will remove dead mites and fecal matter but that matter is so microscopic that unless the vacuum has a Hepa filter that matter will escape through the paper bag and enter the air space adding to the allergic reaction.

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Controlling humidity is the single most important factor in maintaining the reproduction of dust mites. They thrive in 70% or above humidity and because they reproduce in warm moist climates they reach their peak in population in late summer.

Keeping the relativity humidity below 50% and the temperature below 70 degrees will slow the increase of the population. Purchase a hygrometer and check the relativity humidity in your home often.

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Dust mites colonize in mattresses, carpets, and upholstered furniture. They also are very fond of stuffed animals. Change the bedding often, removing the sheets like picking up a picnic blanket full of crumbs. Remove the sheets at the corners and roll carefully toward the center. Pick up the bundle and remove to the laundry. Handle carefully not to disturb the matter because when it becomes airborne it will contaminate the air space for up to eight hours.

Cover the mattress and pillows with barrier cloth covers. Barrier cloth is a 300 count 100% cotton fabric that dust and dust mites can not get through. Note: plastic, vinyl and polyester bedding products are available but can add to the total load of the allergy sufferer.

Good preventive maintenance helps more than any chemical spray. Chemical sprays that are available often contain chemicals that are toxic. Launder the bedding often, hot water/dryer will destroy mites in the bedding. Wash about every 1-2 weeks.

Shampoo carpets with a degreasing detergent at least twice a year.

Keep curtains and upholstered furniture to a minimum and simple. Hardwood, vinyl or tile floors are recommended for the real allergic sufferer.

A good quality Hepa air filter will help to eliminate the airborne matter. Air filters or vacuums will not remove the mite.

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Mold / Fungus

Along with pollens from trees, grasses, and weeds, molds are an important cause of seasonal allergic rhinitis. People allergic to molds may have symptoms from spring to late fall. The mold season often peaks from July to late summer. Unlike pollens, molds may persist after the first killing frost. Some can grow at subfreezing temperatures, but most become dormant. Snow cover lowers the outdoor mold count dramatically but does not kill molds. After the spring thaw, molds thrive on the vegetation that has been killed by the winter cold.

In the warmest areas of the United States, however, molds thrive all year and can cause year-round (perennial) allergic problems. In addition, molds growing indoors can cause perennial allergic rhinitis even in the coldest climates.

What is mold?

There are thousands of types of molds and yeast, the two groups of plants in the fungus family. Yeasts are single cells that divide to form clusters. Molds consist of many cells that grow as branching threads called hyphae. Although both groups can probably cause allergic reactions, only a small number of molds are widely recognized offenders.

The seeds or reproductive particles of fungi are called spores. They differ in size, shape, and color among species. Each spore that germinates can give rise to new mold growth, which in turn can produce millions of spores.

What is mold allergy?

When inhaled, microscopic fungal spores or, sometimes, fragments of fungi may cause allergic rhinitis. Because they are so small, mold spores may evade the protective mechanisms of the nose and upper respiratory tract to reach the lungs.

In a small number of people, symptoms of mold allergy may be brought on or worsened by eating certain foods, such as cheeses, processed with fungi. Occasionally, mushrooms, dried fruits, and foods containing yeast, soy sauce, or vinegar will produce allergic symptoms. There is no known relationship, however, between a respiratory allergy to the mold Penicillium and an allergy to the drug penicillin, made from the mold.

Where do molds grow?

Molds can be found wherever there is moisture, oxygen, and a source of the few other chemicals they need. In the fall they grow on rotting logs and fallen leaves, especially in moist, shady areas. In gardens, they can be found in compost piles and on certain grasses and weeds. Some molds attach to grains such as wheat, oats, barley, and corn, making farms, grain bins, and silos likely places to find mold.

Hot spots of mold growth in the home include damp basements and closets, bathrooms (especially shower stalls), places where fresh food is stored, refrigerator drip trays, house plants, air conditioners, humidifiers, garbage pails, mattresses, upholstered furniture, and old foam rubber pillows.

Bakeries, breweries, barns, dairies, and greenhouses are favorite places for molds to grow. Loggers, mill workers, carpenters, furniture repairers, and upholsterers often work in moldy environments.

Which molds are allergenic?

Like pollens, mold spores are important airborne allergens only if they are abundant, easily carried by air currents, and allergenic in their chemical makeup. Found almost everywhere, mold spores in some areas are so numerous they often outnumber the pollens in the air. Fortunately, however, only a few dozen different types are significant allergens.

In general, Alternaria and Cladosporium (Hormodendrum) are the molds most commonly found both indoors and outdoors throughout the United States. Aspergillus, Penicillium, Helminthosporium, Epicoccum, Fusarium, Mucor, Rhizopus, and Aureobasidium (Pullularia) are also common.

Are mold counts helpful?

Similar to pollen counts, mold counts may suggest the types and relative quantities of fungi present at a certain time and place. For several reasons, however, these counts probably cannot be used as a constant guide for daily activities. One reason is that the number and types of spores actually present in the mold count may have changed considerably in 24 hours because weather and spore dispersal are directly related. Many of the common allergenic molds are of the dry spore type--they release their spores during dry, windy weather. Other fungi need high humidity, fog, or dew to release their spores. Although rain washes many larger spores out of the air, it also causes some smaller spores to be shot into the air.

In addition to the effect of day-to-day weather changes on mold counts, spore populations may also differ between day and night. Day favors dispersal by dry spore types and night favors wet spore types.

Are there other mold-related disorders?

Fungi or microorganisms related to them may cause other health problems similar to allergic diseases. Some kinds of Aspergillus may cause several different illnesses, including both infections and allergy. These fungi may lodge in the airways or a distant part of the lung and grow until they form a compact sphere known as a "fungus ball." In people with lung damage or serious underlying illnesses, Aspergillus may grasp the opportunity to invade the lungs or the whole body.

In some individuals, exposure to these fungi also can lead to asthma or to a lung disease resembling severe inflammatory asthma called allergic bronchopulmonary aspergillosis. This latter condition, which occurs only in a minority of people with asthma, is characterized by wheezing, low-grade fever, and coughing up of brown-flecked masses or mucus plugs. Skin testing, blood tests, X-rays, and examination of the sputum for fungi can help establish the diagnosis. Corticosteroid drugs are usually effective in treating this reaction; immunotherapy (allergy shots) is not helpful.

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