Dust mite allergy

Dust mite allergy is an allergic reaction to tiny bugs that live in house dust. Symptoms of dust mite allergy are like those of hay fever, such as sneezing and runny nose. Many people with dust mite allergy also have symptoms of asthma, such as wheezing and trouble breathing.

Dust mites are related to ticks and spiders. Dust mites are too small to see without a microscope. They eat skin cells that people shed.

Dust mites like places that are warm and humid. In most homes, they're in bedding, padded furniture and carpeting.

Reducing the number of dust mites in the home can help control dust mite allergy. Some people need medicines or other treatments to relieve symptoms and manage asthma.

In dust mite allergies, swelling, called inflammation, of the inside of the nose, causes:

• Sneezing.
• Runny nose.
• Itchy, red or watery eyes.
• Stuffy nose.
• Itchy nose, roof of mouth or throat.
• Mucus running down the back of the throat, called postnasal drip.
• Cough.
• Facial pressure and pain.
• Swollen, discolored skin under the eyes.
• In a child, frequent upward rubbing of the nose.

People who have a dust mite allergy and asthma also might have:

• Trouble breathing.
• Chest tightness or pain.
• A whistling or wheezing sound when breathing out.
• Trouble sleeping caused by shortness of breath, coughing or wheezing.
• Coughing or wheezing that a virus such as a cold or the flu makes worse.

A dust mite allergy can range from mild to severe. A mild case of dust mite allergy may cause a runny nose, watery eyes and sneezing. Sometimes, the condition may be ongoing, called chronic.

With a dust mite allergy, symptoms are likely to be worse while sleeping or cleaning. At those times, the dust mite allergens are more likely to be in the air.

An ongoing dust mite allergy can cause repeated sneezing and coughing; stuffy nose; and facial pressure. It also can cause a flare-up of dry, itchy skin, called eczema, or severe asthma attack.

Some symptoms of dust mite allergy, such as a runny nose or sneezing, are like those of the common cold. It can be hard to know whether the symptoms are from a cold or an allergy. If symptoms last longer than one week, it might be an allergy.

For severe symptoms, such as a badly stuffed-up nose, wheezing or trouble sleeping, call a healthcare professional. Seek emergency care for wheezing or shortness of breath that gets worse quickly or for shortness of breath with little activity.

Allergies occur when the body's protective network, called the immune system, reacts to everyday things such as pollen, pet dander or dust mites. The immune system acts as though whatever causes the allergy is harmful, even though it's not.

The immune system makes proteins called antibodies that protect from invaders that could cause illness or infection. With an allergen, the immune system causes swelling, called inflammation, in the nose or lungs. Long or regular exposure to the allergen can cause the ongoing, called chronic, inflammation linked to asthma.

The following can increase the risk of having a dust mite allergy:

• Having a family history of allergies. Having several family members who have allergies increases the risk.
• Being around dust mites. Having a lot of dust mites around, especially early in life, increases the risk.
• Being a child or a young adult. A dust mite allergy is more likely to come on during childhood or early adulthood.

For people with a dust mite allergy, being around the mites can cause:

• Sinus infections. Swelling in the nose caused by dust mite allergy can block the hollow places called sinuses. This can lead to infections of the sinuses, called sinusitis.
• Asthma. People with asthma and dust mite allergy often have trouble managing asthma symptoms. They might have asthma attacks that need treatment right away.