• House dust mite allergy

    What are the symptoms?

    If you suffer from itchy, reddening or watering eyes, an itchy nose or throat, persistent sneezing, wheezing or sniffling, a runny or clogged nose, cough, congestion or other asthmatic complaints, you may very well be hypersensitive to airborne allergens like pollen or house dust mite allergen.


    Pollen allergy or house dust mite allergy?

    Allergy is diagnosed via the anamnesis (an interview on your personal allergy pattern) and blood analysis (detecting antibodies in the blood) or a skin prick test, where the allergen extract is pricked through the skin with a needle. The test is positive if the prick is followed by an allergic reaction like a red stain or an itchy welt.
    Recent research at Ghent University(*) shows that 13,2 % of the people test positive for tree mix, 25,9% for grass pollen and 25,9 % for house dust mite allergen.

    While pollen are only a concern during pollen season, house dust mite allergen will hit you and impact on the quality of your life every night of the year, predictably and instantly, each time you go to bed.

    (*)full text : http://www.karger.com/Article/FullText/339853?hl=1&q=Katrien%20Blomme

    The short scientific abstract please find here

    What is House Dust Mite Allergy (HDMA)?

    HDMA is an allergic reaction of our immune system on DerP1 and DerF1, enzymes used by the house dust mite to decompose and digest food.

    The main food source of bed mites is human micro skin cells. A person sheds 1.to 1.5 grams of those cells every day; 80% of the house dust particles seen floating in a sunbeam above the bed are micro skin cells. People who inhale these airborne micro-pellets develop allergic symptoms and 60 to 80% of all asthma patients are hypersensitive to HDM excrements. HDMA complaints peak in autumn as people spend more time inside, as it gets darker and the weather gets more humid.

    What is a house dust mite?

    The two most common types of domestic mites are Dermatophagoides Pteronyssinus (the European mite) and Dermatophagoides Farinae (the American version).(*)

    Dustmite Microscope

    The mite is a translucent spider-like creature with 8 legs, typically  0.1-0.4 mm long and 0.5-0.32 wide. Mites do not transmit disease, bite or sting. The only problem with mites is that they produce 200 times their own bodyweight in excrement: 2000 fecal particles and 2000 partly digested enzyme covered dust particles.

    Mites are found in every home and their favourite spot is the bed: They thrive in a warm (20-25°C), humid and dark environment with plenty of food. People provide the heat and humidity while sleeping and there are "mountains" of micro skin cells to eat. 

    Mites need a relative humidity of 80-85% to have access to water. They obtain essential water from moist food and from a mechanism of crystals in the armpits. Lower humidity immediately results in a lower activity. 45% RH is a bare minimum and 55% RH is needed for reproduction. Frost destroys the armpit crystals and also direct UV light kills mites. Mites moult in 6 phases from an egg to an adult in about 1 months' time. Females produce 40 to 150 eggs in their lifetime and mites live between 30 (male) to 100 days (female). Mites have no eyes, no antennae, no stomach (only pouches in which the enzyme decomposes food).

    (*) see electron microscope image - © G. Bauchan and R. Ochoa

    Do you have House Dust Mite allergens in bed ? Let’s find out!



    66% of all mites are found in bed, where people spend on average 52.5 hours per week (source Allergy UK) and they are fully exposed to the allergens of the house dust mite.

    Every mattress that has been used for 6 months contains mites (100.000 to 10 million). If you want to find out if your mattress contains allergens, you can do a Rapid Test : the “Acarex Test” and “Dräger Bio Check Allergen Control” are quick and reliable. Scientist use more professional devices and reproducible techniques to measure DerP1 (Elisa test) or even a range of allergens like house dust mite, cat, rat, cockroach allergen (Maria test).

    How to reduce allergy?

    It is advised to see a doctor for diagnosis and treatment. The options are medication against the symptoms (inhalators, eye-drops, nose-spray, cortisone tablets) or immune-therapy. This therapy lets the immune system get used to the allergen (injection or daily drops).The immune system is in this way re-programmed, de-sensitized.

    For all allergic people it is advised to avoid contact with allergens and to sanitize the environment.



Tips to avoid contact with allergens

A low relative humidity (RH) in the room AND in bed is critical

No excessive heating, room temperature 16-18 °C

Maximize ventilation in the room

Clean the floor, walls and woodwork with water or a wet cloth

Put your pillow in the deep freezer for a week, wash afterwards

No pets, no plants, no dust traps (like teddy bears) in the room

Use hard floorings like wood, stone tiles or vinyl

Use probiotics to clean up the allergens

Replace and wash bed linen, blankets, duvets every week at min. 54°C-130°F

Leave the bed linen hanging outside as often as practical, leave the bed open all day

No undressing in the bedroom, do it in the dressing room or in the bathroom

Avoid curtains and carpets

Effective vacuum cleaning using a HEPA (High Efficiency Particulate Air ) type filter that removes 99.97% of even the smallest airborne particles (diameter 0.3µm).

Effective vacuum cleaning takes time : after vacuuming a carpet at 1 minute per m² only 5% of the mites and 4% of the allergen dust are gone. After 40 minutes per m² that becomes 75% of the mites and 50% of the dust.

Mattress and pillow encasings reduce the breathability of the sleeping system.