Dust Mite Allergy

Dust Mite Allergy is triggered by house dust mites and their droppings. Dust mites are one of the major allergens(1) that causes year-round allergy symptoms.(9)

Dust Mites are found almost everywhere people live. They are small, eight-legged arachnoids of
0.2-0.4 mm size.(2) With the naked eye, they can still be seen at favorable light conditions.(1) For ideal growth, mites require temperature ranging from 15-32°C and humidity between 70 and 85%.(1)

Mites feed mainly on shed human and pet skin scales or flakes. An adult person produces per day
1.5 grams of skin flakes, which can feed about 100,000 mites.(1)

Mircoscopic HDM Microscopic image of House Dust Mites

In the home, mites are found in all the places where they can find the necessary moisture, heat, darkness and food. The mites are common in the dust of soils, upholstery furniture and beds, especially when the humidity is high. In the apartment, the mattress is the most important mite and mite allergen reservoir. Mites find ideal living condition in bed(1). People usually spend around 8 hours daily in bed - which corresponds to a high level exposure to the mites.

Dust mites are found in mattress, pillows, carpets and upholstery. With every movement we make the dust is stirred. Settled dust becomes airborne while performing certain activities like dusting, vacuuming or making the bed.(8) The faecal pellets and smaller allergen-bearing particles become temporarily suspended in the air and may be inhaled.(3) Especially vacuuming increases allergen load of the room air because the fecal particles are so small that they can be blown out through the exhaust filter back into the room. Mites can particularly hide well in a long pile rug. This offers mites excellent protection and good chances of survival because they can cling to the fibres and are barely affected by the vacuum cleaner.(1)

Allergy due to house dust mites is caused due to protein particles present in both the mite body and mite droppings.(3,9)

Adapted from: Tovey ER, et al. Nature.1981 Feb 12; Vol 289:592-593. Image of Mite Body and its droppings as seen under the mircroscope

The allergic symptoms are triggered when these mite bodies and droppings are inhaled by a mite allergic patient. The immune system of the patient classifies these allergens incorrectly as dangerous and makes antibodies – that is immunoglobulin E(IgE). In the further course of the allergic reaction, various chemicals such as histamine are released that triggers different organs such as the nose, eyes, lungs & results in allergic symptoms.(3,4)

As the house dust mites are commonly found in the bed, allergy due to mites presents predominantly indoors and with symptoms often seen early in the morning or at night when the patient is in the bed. Additionally, the symptoms persist all year-round (perennial) but peaks during the humid weather.(3,8)

Allergy to dust mites can manifest as:

  • Allergic rhinitis or hay fever, with symptoms such as blocked or running nose, itching or sneezing.(3,9)
  • Allergic rhino-conjunctivitis in addition to the above symptoms the eyes are red and
    watery.(3,9)
  • Allergic asthma, if the lower respiratory tract is exposed to and affected by house dust mite allergy, wheezing, breathlessness or difficulty in breathing and cough could be present.(3,9)

house dust mite All year-round or perennial indoor allergic symptoms and reacting to dust, which is located in your home, along with early morning or night symptoms near the bed reinforces the suspicion of a dust mite allergy.

Only a specialist (allergist) with a focus on allergology can clearly identify whether you have a house dust mite allergy. Firstly, the doctor will discuss your medical history which provides vital information. This helps the Doctor to get important information on the type of allergy and the possible triggers.

To identify the allergy trigger the Doctor may perform an allergy test. The most common and recommended allergy test is the skin prick test. Skin prick test is also the preferred test(5) as it is reliable, inexpensive and provides quick results. Rarely an intradermal test may be used. A blood test in the laboratory may also be utilized to detect allergen-specific IgE. However, both the skin tests and blood analysis only show a sensitivity to the allergen in question, a so-called sensitization. This is not tantamount to a dust mite allergy. It is a dust mite allergy, only when the medical history coincides with the sensitization.(6)

To confirm the skin test results or if there is doubt in the diagnosis, provocation test can be performed. If the patient responds to the allergen with typical allergy symptoms such as runny nose, sneezing, watery eyes, the diagnosis is confirmed and the causative allergen is identified without a doubt.(6)

House dust mites (HDM) are by far the most common aeroallergen implicated in allergic individuals. The percentage of dust mite sensitized patients in India varies in the different zones.(7)

mite allergy

For the treatment of allergy your specialist (allergist) may offer three options:(4)

mite allergy

Ideally, he combines the measures to get your complaints as rapidly and effectively under control.

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IND/07/17/ALGY/047/EXP 07/19

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