Allergy to mold, dander, dust

Causes and Risks:
Allergies are caused by hypersensitivity of the immune system, leading to a misdirected immune response . The immune system normally protects the body against harmful substances such as bacteria, viruses, and toxins . Allergy occurs when the immune system reacts to substances (allergens) that are generally harmless and in most people do not cause an immune response.

Allergy to environmental particles is a type of allergic rhinitis ( hay fever ). Hay fever usually involves an allergic reaction to pollen. However, people may develop an allergic reaction to other particles in the environment.

Many people are allergic to mold. Mold spores are carried in the air and may be present all year long. Mold is most prevalent indoors in damp locations and in swamp coolers, bathrooms, washrooms, fabrics, rugs, stuffed animals, books, wallpaper, and other "organic" materials. Outdoors, mold lives in the soil, on compost, and on damp vegetation.

Dust is another common allergen . House dust contains microscopic particles of pollen, mold, fibers from clothing and other fabrics, detergents , and microscopic insects (mites). Mites, including small fragments of dead mites, are the primary causes of dust allergy.

Many people are allergic to animals. Most people are not allergic to the animal's fur or feathers. They are actually allergic to the small scales of skin (dander) that the animal sheds. Some people are allergic to the animal's saliva, particularly cats (whose saliva contains a protein known to cause allergy). Saliva exposure occurs if the animal licks the person. It may also occur from petting the animal after it has groomed itself or by touching an object that the animal has recently licked or chewed.

A few people develop allergies to other irritants in the environment, including smoke, fumes from industries or cleaning products, tobacco, powder ( face powder , baby powder, and so on.), laundry detergents, and other common substances.

When an allergen enters the body of a person with a sensitized immune system, it triggers antibody production. Histamine and other chemicals are released by body tissues as part of the immune response. This causes itching , swelling of affected tissues, mucus production, muscle spasms , hives and rashes , and other symptoms.

Symptoms vary in severity from person to person. Most environmental allergens contact the skin or are inhaled. Therefore, most symptoms affect the skin or the breathing passages.

Many disorders are associated with, triggered, or worsened by allergies. These include eczema , asthma , and many others.

Allergies are common. Heredity, environmental conditions, number and type of exposures, emotional factors ( stress and emotional upset can increase the sensitivity of the immune system), and many other factors can indicate a predisposition to allergies.

Prevention:
There is no known way to prevent allergies . Symptoms may sometimes be prevented by avoiding known allergens.

Mold spores are everywhere. Minimize exposure by keeping rooms dry (using a dehumidifier if necessary). Stay indoors during summer and fall, when mold is most prevalent. Discard moldy or mildewed articles (books, toys, shoes, and so on). Use synthetic fabrics for clothing and household furnishings whenever possible. Disinfect bathrooms, basement walls, and furniture with diluted bleach or other appropriate disinfectant solution.

Dust exposure is minimized by frequent cleaning. Vacuum frequently, preferably using a
small-pore filter to capture dust mites. Damp-mop and dust often. Eliminate as many "dust catchers" as possible, including rugs, bed ruffles or canopies, and curtains. Wash rugs, bedding, and furniture coverings weekly if possible. Central heating and air-conditioning systems may be helpful, particularly if they include special filters to capture dust.

People who are allergic to animals may need to avoid keeping pets. Frequent bathing and
grooming of the pet (preferably by someone who is not allergic to the animal) may allow some people to keep their pet. Allergy to animals may also include allergic reaction to wool, which may contain tiny amounts of dander (skin scales ).

Avoid other environmental irritants whenever possible.

Symptoms:



Signs and Tests:
History is important in diagnosing allergies , including whether the symptoms vary according to time of day or the season and possible exposures such as having a pet in the household.

Testing may reveal the specific allergen (s).

  • Skin testing is the most common method of allergy testing . This may include intradermal, scratch, patch, or other tests.
  • RAST
  • Occasionally, the suspected allergen is dissolved and dropped onto the lining of the lower eyelid ( conjunctiva ) as a means of testing for allergies.
  • Other testing to determine the specific allergen may include various types of "use" or "elimination" tests where suspected items are eliminated and/or introduced while the person is observed for response to the substance.

This disease may also alter the results of the following tests:



Treatment:
The goal of treatment is reduction of allergy symptoms.

Avoidance is the best treatment (see Prevention). Complete avoidance of environmental allergens may be impossible, but exposure may be minimized in many cases.

Antihistamines such as diphenhydramine often provide good relief of mild to moderate symptoms. Decongestants may also be helpful in reducing symptoms such as nasal congestion . Corticosteroids such as dexamethasone or prednisone reduce the immune response and may be prescribed to reduce severe symptoms. Inhaled cromolyn sodium may be used for the treatment of asthma and a cromoly sodium spray is available for allergic rhinitis . An ophthalmic version of cromolyn sodium has been intermittently available for allergy sufferers with itchy bloodshot eyes . Other medications may vary depending on the type and severity of allergic reaction symptoms.

Specific illnesses that are caused by allergies (such as asthma, hay fever , and eczema ) may require other treatments.

Desensitization (immunotherapy, "allergy shots") is occasionally recommended if the allergen cannot be avoided. It includes regular injections of the allergen, given in increasing doses (each dose is slightly larger than the previous dose) that may "acclimatize" the body to the antigen .

Prognosis:
Most allergies are readily treated. However, treatment only affects that exposure, so subsequent exposures cause another allergic reaction .

People who are allergic to mold may also be allergic to penicillin, which is derived from a variety of mold. They may also be allergic to blue cheese, which is an ingredient of some salad dressings.

Rarely, people may outgrow an allergy as the immune system becomes less sensitive to the allergen . However, as a general rule, once a substance has provoked an allergic reaction it continues to affect the person.

Desensitization may cause uncomfortable side effects (such as hives and rash ) and may have dangerous side effects such as anaphylaxis . It often requires years of treatment and is effective in about two-thirds of cases.

Complications:



Call Your Healthcare Provider:
Call for an appointment with your health care provider if severe symptoms of allergy occur, if previously successful treatment has become ineffective, or if symptoms do not respond to treatment.