Dust mite allergy symptoms caused by inflammation of nasal passages include:
- Runny nose
- Itchy, red or watery eyes
- Nasal congestion
- Itchy nose, roof of mouth or throat
- Postnasal drip
- Facial pressure and pain
- Swollen, blue-colored skin under your eyes
- In a child, frequent upward rubbing of the nose
If your dust mite allergy contributes to asthma, you may also experience:
- Difficulty breathing
- Chest tightness or pain
- An audible whistling or wheezing sound when exhaling
- Trouble sleeping caused by shortness of breath, coughing or wheezing
- Bouts of coughing or wheezing that are worsened by a respiratory virus such as a cold or the flu
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.
When to see a doctor
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.
What causes the allergic reaction
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.
The following factors increase your risk of developing a dust mite allergy:
- Having a family history of allergies. You're more likely to develop a sensitivity to dust mites if allergies are more common in your family.
- Exposure to dust mites. Being exposed to high levels of dust mites, especially early in life, increases your risk.
- Being a child or a young adult. You're more likely to develop dust mite allergy during childhood or early adulthood.
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.