In people with allergies, the immune system treats them as if they were harmful substances, causing a cascade of events, including inflammation and the production of immune response modulators.
Asthma attacks can be triggered by allergies. Allergic asthma is the most common type of asthma. An allergic response results in the release of histamines and immunoglobulin E (IgE). Too much IgE can cause inflammation of the airways and lead to an asthma attack.
The most important allergens for people with allergic asthma are those that are inhaled. Respiratory allergies affect approximately 24.4 million people in the United States. Food allergies can cause asthma, although this is rare. About 4.8 million children have food allergies.
The symptoms of allergic asthma are basically the same as those of non-allergic asthma and include chest tightness, coughing, rapid breathing, shortness of breath and wheezing.
Common triggers include:
Cockroaches. These insects live everywhere from the coldest places on Earth to tropical areas. The body parts, droppings and saliva of cockroaches are considered allergens.
Dust mites. These are microscopic, spider-like insects that feed on human skin flakes. Dust mites can be found in bedding, carpets, clothing, furniture, mattresses, pillows, stuffed animals and upholstery. As with cockroaches, the body parts and droppings of dust mites are considered allergens.
Food Allergens. Foods that can cause allergic asthma include cow's milk, eggs, fish, peanuts, shellfish, soy, sulfites (often used as preservatives) and tree nuts.
Mold. Mold can grow anywhere there is moisture. Outdoors, molds live in the soil and on leaves and other plant debris. Indoors, mold can be found in damp basements, near leaky pipes or in wet shower stalls, among other places. Molds reproduce by producing tiny spores that spread through the air.
Pets. Pet dander, feces, hair and saliva are all considered allergens. People who have pets can carry these allergens with them and find them where no pets have been.
Pollen. Pollen is produced by plants, primarily the male species of flowering plants. These airborne particles are a common respiratory allergen. They often have a peak season of production but can live in a home and in air ducts year round.
Below are ways to avoid triggers.
Use bug sprays but not near people.
Use roach baits or traps.
Avoid curtains and drapes and use simple blinds instead of mini-blinds.
Change filters on air conditioners and heaters regularly.
Control indoor humidity.
Cover air ducts with filters.
Install non-carpeted flooring.
Keep only washable stuffed animals.
Store books and clothes in closed closets or drawers.
Use feather-free bedding and pillows.
Ventilate damp and wet areas.
Avoid raking leaves or working with hay or mulch.
Buy cleaning products that kill and prevent mold.
Keep plants out of bedrooms.
Remove clothes from the washing machine as soon as the cycle is finished.
Avoid areas where mold can grow, such as basements, crawl spaces and garages.
Store firewood outside.
Turn on an air conditioner when possible.
Use a mold inhibitor when painting walls.
Avoid owning pets or adopt hypoallergenic pets.
Bathe your pets weekly.
Give up long visits to people with pets.
Limit pet access outside of rooms.
Avoid hanging laundry outside to dry.
Keep windows closed during pollen season.
Limit time spent outdoors during periods of high pollen counts.
Wash your body and clothes when you come home from the outdoors.
Wear a mask when gardening, mowing, weeding, etc.
Treatment options include the following.
Antibody treatment. This treatment uses medications that prevent the body's cells from triggering an inflammatory response. These treatments are reserved for patients with severe asthma that is not controlled by other means.
Anti-leukotriene drugs. These drugs inhibit the effects of leukotrienes that are produced as part of an immune response, thereby reducing inflammation.
Immunotherapy. Immunotherapy regularly introduces a small amount of allergen into the patient's body. Once the body has become accustomed to being exposed to the substance(s), it reacts less. It is administered by injection or as a sublingual tablet. The disadvantages are cost and the fact that it takes several years for a patient to develop tolerance.
Inhaled Corticosteroids. If a rescue inhaler is used too often, a doctor may prescribe an inhaled corticosteroid as a maintenance medication. These medications work to decrease inflammation. Inhaled corticosteroids can help the lungs work better after future asthma attacks if they are used regularly.
Long-acting bronchodilators. These are used regularly to reduce the amount and severity of asthma symptoms. They are usually given twice a day, and their effect lasts about 12 hours.
Oral corticosteroids. These medications are usually only used for severe attacks. They work by decreasing inflammation in the lungs. Long-term use of oral corticosteroids can cause serious side effects, so they are only used as short-term treatment.
Rescue inhalers (short-acting bronchodilators). These medications work quickly to open up the airways in the lungs. Everyone with asthma should have a short-acting bronchodilator. The effects last 4 to 6 hours.
It is important to consider that although there is a strong link between allergies and asthma, not all people with allergies have asthma attacks and not all people with asthma have allergies.
Many people have more than one trigger, so it is important to be aware of different triggers when trying to manage symptoms. Triggers can also change over time, and people can develop allergies at any time in their lives.
Being informed and taking steps to limit exposure can help manage allergies and asthma effectively.