House Dust Mite

What is HDM Allergy?

HDM allergy is an allergic reaction to tiny bugs that commonly live in house dust. HDM may be the most common cause of year-round allergy and allergic asthma.

In people allergic to HDM, it is often not only the mite itself but also proteins in their droppings which cause the allergy. Each mite produces about 20 of these waste droppings every day and the droppings continue to cause allergic symptoms even after the mite has died.

If you have allergic symptoms like a runny nose, itchy eyes or cough, tiny creatures living in your home might be the reason for your problems. Although you cannot see them, you may be feeling their effects only too well.

They are, House Dust Mites and they live in many homes throughout the world.

What is a HDM?

Too small to be seen with the naked eye, a HDM measures only about one-quarter to one-third of a millimeter. HDM are close relatives of ticks and spiders. HDM do not bite people. They represent no danger to people who are not allergic to them.

Where are they found?

HDM trapped in the fibers of bed linens, furniture cushions and carpets. These materials also hold moisture well. Consequently, bedrooms are ideal habitats for HDM. HDM are attracted to your bed because they live off the skin cells that we all shed each night. They also live in upholstered furniture.

Here is the problem: As you sleep, your skin sloughs off and works its way down into your bedding. An average adult person may shed up to 1.5 grams of skin in a day, this is enough to feed 1 million HDM. If the air in your room is humid, HDM get into your bed and pillow and happily grow into large colonies. Furthe more, your own bodycreates humidity as you breathe and perspire. Trying to kill the HDM will only have a limited effect, because the HDM faeces and the dead mite bodies remain and will still cause problems

What are the treatment options available?

The first treatment for controlling HDM allergy is avoiding HDM as much as possible. When you minimize your exposure to HDM, you should expect fewer allergic reactions or the reactions should be less severe. However, it is impossible to eliminate HDM from your environment. You may also need medications like antihistamines, corticosteroids etc to control symptoms.

The only causative therapy for HDM allergy is the allergen immunotherapy. You can “train” your immune system not to react exaggerated to an allergen anymore. This is done through a series of allergy shots called immunotherapy. One to two weekly shots expose you to very small doses of the allergen, in this case, modified/processed versions of the mite proteins that causes an allergic reaction. The dose is gradually increased, usually during a three-to six-months period. Maintenance shots are needed every four weeks for three to five years. Immunotherapy is usually used when other treatments like antisymptomatic medication are not satisfactory.

What are the signs and symptoms of HDM allergy?

Mild Cases

Sneezing
Runny nose
Itchy, red or watery eyes
Nasal congestion
Itchy nose, roof of mouth or throat
Postnasal drip
Cough
Facial pressure and pain
Swollen, blue-colored skin under your eyes
Frequent upward rubbing of the nose in children

Severe Cases

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

What are the risk factors?

The following factors increase your risk of developing a HDM allergy:

Having a family history of allergies
You are more likely to develop a sensitivity to HDM if allergies are more common in your family.
Exposure to dust mites
Being exposed to high levels of HDM, especially early in life, increases your risk.
Being a child or a young adult
You are more likely to develop HDM allergy during childhood or early adulthood.