What are dust mites? Dust mites live in bedding, trigger allergies through house dust and can thus cause asthma. The peak breeding season for house dust mites is between May and October – when temperatures and humidity are ideal for them.
This may sound a little on the sinister side, but you are never alone in your bed. Let us explain. This is because microscopically small arachnids, also known as house dust mites, are always settling there. House dust mites trigger allergies in many people and are found in every household and every bed – without exception.
As unsettling as this may be, there is no need to despair. In this article, we’ll tell you all about how to relieve or even prevent dust mite allergy symptoms on a daily basis. If our trusty tips fail to relieve your symptoms, there are also other forms of dust allergy treatment out there for you to try.
What are dust mites?
A dust mite, also known as a house dust mite, lives in the dust of our houses. They are eight-legged arachnids up to 0.5 millimetres in size that we cannot see with the naked eye. They mainly feed on skin flakes and mould and prefer to stay in pillows, blankets, mattresses and upholstery. Up to ten million house dust mites can be found in a single bed.[2, 3] In total, there are 13 different dust mite species.
Did you know that dust mites have nothing to do with dirt and bad hygiene? The little animals can be found in every household. But if you air out your home frequently and wash your bedding often, you can significantly reduce the number of dust mites in your home.
Are dust mites everywhere?
A dust mite’s favourite climate is in an environment where it is 25 to 30 degrees Celsius and over 70 degrees in terms of humidity. If it is warm and humid, dust mites are active and reproduce quickly. Since we give off heat and moisture when we sleep, we create the ideal habitat for dust mites between our bedding and the mattress.
On the other hand, these arachnids hate cold, dry climates. The colder it gets, the slower they reproduce. If humidity is below 50 per cent, the house dust mites lose too much fluid and die. Nevertheless, allergies are often particularly severe when we turn on our heating in autumn and the air becomes drier – because dead dust mites decompose, leaving their allergens in the dust.  Even if the outside temperatures in winter are far too low for dust mites, they can hibernate in our mattresses.[6, 7]
House dust mites and high altitudes
For a long time, it was said that house dust mites are hardly found at altitudes above 1,200 to 1,800 metres. However, a study from 2016 suggests that house dust mites can thrive at high altitudes – it is not the altitude that is decisive, but the temperature and humidity in a mattress.
According to the researchers, climate change and better insulated and heated buildings have improved the conditions for mites even at high altitudes in the Alps. Nevertheless, studies suggest that high-altitude air is good for allergy and asthma sufferers because there is less pollen and and less fine dust in the mountains. In addition, UV radiation is more intense, which strengthens the immune system and stimulates vitamin D production in our bodies.[8–10]
What causes dust mite allergy?
House dust allergy is a type I allergy. In such an allergy, our body classifies harmless proteins, called allergens, as dangerous. Such allergens are found in the faeces of house dust mites. In fact, up to 250,000 balls of dust mite excrement can be found in one gramme of dust.
How does a dust allergy develop?
When we are allergic, our body produces specific IgE antibodies to fight off the allergens in dust mite faeces. This causes the body’s cells to release messenger substances, especially histamine, when we encounter these faeces. These messenger substances trigger inflammatory reactions that are accompanied by the typical allergy symptoms such as sneezing and itchy eyes.[3, 11]
Who is affected by a dust allergy?
Researchers have recognised that parents of house dust allergy sufferers also often suffer from allergies, such as hay fever – also known as a pollen allergy. A tendency to develop allergies therefore seems to be genetic. If you have allergies yourself, it is worth looking out for dust mite allergy symptoms in your children.[12, 13]
Did you know that people were already aware of dust allergies triggering allergic rhinitis in the 17th century? It was not until 1964 that researchers found mites in house dust and claimed them to be the source of dust allergy.
Can dust mite allergy cause asthma?
If you as an allergy sufferer repeatedly come into contact with a large number of house dust mites, dust mite allergy symptoms can worsen over time. Your nasal mucosa can become permanently inflamed, which is accompanied by itching and a constantly blocked nose. In addition, these symptoms can spread to your lower airways.
If this happens, allergic asthma may develop. House dust mites are considered one of the most common triggers for this type of asthma, along with a pollen and animal hair allergy.
What are typical dust mite allergy symptoms?
Allergy sufferers react to house dust especially at night and in the morning when they are in bed amongst the allergens. Even if you stir up the dust when vacuuming or mopping, you may experience discomfort.
What are the symptoms of a house dust allergy?
Typical dust mite allergy symptoms include:[5, 15]
- A stuffy nose, watery rhinitis and sneezing episodes
- Watery and itchy eyes
- Itchy and reddened skin, triggering a neurodermatitis flare-up (this is in rare cases)
How do you get tested for dust mite allergy?
If you suspect that you or your child is allergic to house dust, you can test this in several ways. Specialists in allergology, often paediatricians, perform a prick test. This involves a doctor scratching a solution containing the allergen into the skin, usually on the arm or back, and seeing if this results in redness and swelling.
You can also try to diagnose a dust allergy with a blood test by either asking your doctor for a blood test or performing a house dust allergy test within the comfort of your own home. Both a prick test and blood test tell you whether your body produces more IgE antibodies when it comes into contact with house dust mite allergens. Doctors refer to this as sensitisation to the allergen.
However, sensitisation does not mean that you have an allergy, per se. Doctors can make sure with a provocation test, during which the allergen is put into your nose or lungs under medical observation. Doctors then measure, among other things, how much your nasal mucous membranes swell and whether the volume of air you breathe in and out changes.
According to some studies, 16 per cent of adults and 22 per cent of children in Germany show such sensitisation to house dust. More often, adults have allergies, such as a specific grass or pollen allergy – for example, a birch pollen allergy – insect venom allergy and a food allergy.[13, 14]
Cross-reactivity: what about other allergies?
If you are allergic to house dust mites, there is a relatively high chance that you will also react to molluscs and crustaceans – for example, if you eat prawn, crab, lobster or mussels. The culprits are proteins in the animals that are similar to the mites’ allergens. Doctors call such a case a cross-allergy or cross-reactivity.[19–21] Other cross-reactions occur between latex and birch, for example.
If in doubt about any whether you have other allergies, you can always opt to take a food allergy test to rule out any suspicion that your allergy symptoms are triggered by cross-reactivity. Such allergy tests are usually blood tests that screen for IgE antibodies produced when a certain allergen has entered your body. Results can provide a great and insightful initial indication of foods that your body is sensitive to, which you can then chase up more closely with a doctor.
Dust allergy treatment: relieving dust mite allergy symptoms
By far the most effective dust allergy treatment against the symptoms of a dust allergy is to reduce the number of house dust mites living in your home. To relieve dust mite allergy symptoms, you can also use nasal rinses and take certain medication. Antihistamine tablets and sprays with glucocorticoids are usually very helpful, and you can get some of these allergy medicines over the counter at the pharmacy. However, these medicines are not suitable for long-term use.
How does immunotherapy for a dust allergy work?
Since house dust allergies occur all year round, a permanent solution is needed for people with severe allergies. If it is not enough to reduce the number of dust mites by airing and washing your bedding, allergen immunotherapy can help as a form of dust allergy treatment. In this treatment, which also called hyposensitisation, doctors repeatedly administer the allergen in increasing doses over at least two years.
This is done either by injecting the allergen into the skin or by giving tablets or drops under the tongue. In many cases, the immune system gets used to the allergen through immunotherapy and symptoms go away. In recent years, medical research has suggested that immunotherapy treatment for a dust allergy can also help against allergic asthma.[14, 22, 23]
Tips for house dust allergy sufferers
If you are allergic to dust mites, the first thing you should do is try to make life difficult for the little creatures, especially in your bedroom. The following tips will help you prevent dust mite allergy symptoms from becoming a problem for you or your children.[15, 24-26]
Our 12 tips for fewer dust mites
- Ventilate extensively! Airing your bed several times a day ensures fresh air, which absorbs moisture from the bed.
- Place a special cover over your mattress. Hypoallergenic bedding also prevents dust mite allergens from accumulating in your mattress. You can wash the cover when you change your bed sheetings and wash them every few months.
- A waterbed is a good alternative for allergy sufferers – here, dander cannot accumulate in the mattress, and waterbeds are also easy to clean.
- Get cotton bedding and air it daily.
- Wash your bedding every one to two weeks at 60 degrees Celsius.
- Do not make your bed. Yes, you read that correctly! In a made bed, heat and liquid are less able to escape from the mattress.
- Other textiles in the room, such as pillows, blankets and curtains, should be washed at 60 degrees Celsius at least every three months.
- Get rid of unnecessary material on which mites can settle – such as upholstered furniture, decorative cushions and cuddly toys.
- If your favourite cuddly toy has to be in the bed with you, wash it regularly at 60 degrees Celsius. If this is not possible, put it in the freezer for 24 hours – this also kills the dust mites.
- Do not put plants in the bedroom – they increase the humidity in the room.
- Pets, like humans, shed dander, which serves as food for mites. Keep them out of the bedroom, if possible.
- Leave the vacuuming and dusting to someone who does not have a dust allergy, and get a hoover with a fine dust filter.
These tips are only useful for people who are allergic to house dust. Those who do not have an allergy will probably not be able to prevent an allergy from developing in the future with the measures listed above.
Dust allergy & dust mite allergy symptoms – at a glance
What causes dust mite allergy?
House dust allergy sufferers react to the excrement of house dust mites, which mix with dust particles. House dust mites prefer to live in our beds, where they feed on skin flakes and feel at home in a humid and warm climate. Dryness and the cold are detrimental to dust mites.
What are typical dust mite allergy symptoms?
Dust allergy symptoms appear mainly in the morning through sniffling and sneezing and itchy eyes. Less frequently, allergy sufferers may experience red and itchy skin. For neurodermatitis sufferers, a dust allergy can trigger skin flare-ups.
Are there forms of dust allergy treatment?
The most effective form of dust allergy treatment is to reduce the number of dust mites in the bedroom, especially through extensive airing and washing bedding at 60 degrees Celsius at least every two weeks. If taking action against house dust mites in your home does not help, immunotherapy can alleviate symptoms.
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