Dust mite allergy is an allergic reaction to tiny bugs that commonly live in house dust. Signs of dust mite allergy include sneezing and runny nose. Many people with dust mite allergy also experience signs of asthma, such as wheezing and difficulty breathing.
Dust mites, close relatives of ticks and spiders, are too small to see without a microscope. Dust mites eat skin cells shed by people, and they thrive in warm, humid environments. In most homes, bedding, upholstered furniture and carpeting provide an ideal environment for dust mites.
Steps to reduce the number of dust mites in your home can often control dust mite allergy. Medications or other treatments may be necessary to relieve symptoms and manage asthma.
Dust mite allergy symptoms caused by inflammation of nasal passages include:
If your dust mite allergy contributes to asthma, you may also experience:
A dust mite allergy can range from mild to severe. A mild case of dust mite allergy may cause an occasional runny nose, watery eyes and sneezing. In severe cases, the condition may be ongoing (chronic), resulting in persistent sneezing, cough, congestion, facial pressure or severe asthma attack.
Some signs and symptoms of dust mite allergy, such as a runny nose or sneezing, are similar to those of the common cold. Sometimes it's difficult to know whether you have a cold or an allergy. If symptoms persist for longer than one week, you might have an allergy.
If your signs and symptoms are severe — such as severe nasal congestion, difficulty sleeping or wheezing — call your doctor. Seek emergency care if wheezing or shortness of breath rapidly worsens or if you're short of breath with minimal activity.
Dust mites eat skin cells people have shed, and rather than drinking water, they absorb water from humidity in the atmosphere. They thrive in temperatures between 65 and 84 F (18.5 and 29 C) and a relative humidity higher than 50 percent.
House dust is easily trapped in the fibers of bed linens, furniture cushions and carpeting. These materials also hold moisture well. Consequently, bedrooms are ideal habitats for dust mites.
Dust also contains the feces and decaying bodies of dust mites, and it's the proteins present in this dust mite "debris" that are the culprit in dust mite allergy.
Allergies occur when your immune system reacts to a foreign substance such as pollen, pet dander or dust mites.
Your immune system produces proteins known as antibodies. Some of these antibodies protect you from unwanted invaders that could make you sick or cause an infection. When you have allergies, your immune system makes antibodies that identify your particular allergen as something harmful, even though it isn't. When you inhale the allergen or come into contact with it, your immune system responds and produces an inflammatory response in your nasal passages or lungs. Prolonged or regular exposure to the allergen can cause the ongoing (chronic) inflammation associated with asthma.
Your doctor may suspect dust mite allergy based on symptoms, an examination of your nose, and your answers to his or her questions.
He or she may use a lighted instrument to look at the condition of the lining of your nose. If you have an allergy to something airborne, the lining of the nasal passage will be swollen and may appear pale or bluish.
Your doctor may suspect a dust mite allergy, based on your comments. For example, if your symptoms are worse when you go to bed or while cleaning — when dust mite allergens would be temporarily airborne — you may have dust mite allergy.
If you have a pet — another common source of allergies — it may be more difficult to determine the cause of the allergy, particularly if your pet sleeps in your bedroom. The source of your allergy may be clearer after you take steps to reduce levels of the possible allergens from your home.
Your doctor may suggest an allergy skin test to determine what you're allergic to. You may be referred to an allergy specialist (allergist) for this test.
In this test, tiny amounts of purified allergen extracts — including an extract for dust mites — are pricked onto your skin's surface. This is usually carried out on the forearm, but it may be done on the upper back.
Your doctor or nurse observes your skin for signs of allergic reactions after 15 minutes. If you're allergic to dust mites, you'll develop a red, itchy bump where the dust mite extract was pricked onto your skin. The most common side effects of these skin tests are itching and redness. These side effects usually go away within 30 minutes.
In some cases, a skin test can't be performed because of the presence of a skin condition or because of interactions with certain medications. As an alternative, your doctor may order a blood test that screens your blood for specific allergy-causing antibodies to various common allergens, including dust mites. This test may also indicate how sensitive you are to an allergen.
Ongoing (chronic) inflammation of tissues in the nasal passages caused by dust mite allergy can obstruct your sinuses, the hollow cavities connected to your nasal passages. These obstructions may make you more likely to develop infections of the sinuses (sinusitis).
People with asthma and dust mite allergy often have difficulty managing asthma symptoms. They may be at risk of asthma attacks that require immediate medical treatment or emergency care.
Avoiding exposure to dust mites is the best strategy for controlling dust mite allergy. While you can't completely eliminate dust mites from your home, you can significantly reduce their number. Use these suggestions:
The following factors increase your risk of developing a dust mite allergy: