House dust allergy: symptoms, treatment options and prognosis of allergy to dust mites.

The commonly used term "house dust allergy" is misleading. This is because house dust allergy sufferers are not allergic to house dust in general. The allergy is to the so-called house dust mites, their droppings and dead mites, which are - also - found in house dust. However, excrement and remains of the small arachnids are not only found in house dust, but especially in mattresses, curtains, carpets and cuddly toys. The correct name is: house dust mite allergy. The leading symptoms of dust mite allergy are itchy, burning eyes, runny nose or a blocked nose and cough and are therefore very similar to those of hay fever. So how can the allergies be differentiated from each other? How can a dust mite allergy be treated? And what can those affected do themselves?

Table of contents:

• Background: What is a house dust mite allergy?
• Recognize house dust allergy: What are the symptoms?
• Confirming suspicions: How is a diagnosis made (at the doctor's office)?
• Triggering factors: How does a house dust mite allergy develop?
• Relieve symptoms: How is house dust allergy treated?
• Becoming active yourself: What can those affected do themselves?
• Prognosis: What is the course of the disease with and without therapy?
• Tips for seniors: What are the special features to consider?

In the case of so-called house dust allergy, those affected do not primarily react allergically to the house dust, but to very specific components in the house dust. House dust is composed of a very wide variety of substances. The most frequently encountered contents include:

• Textile fibers
• Fungal spores
• Bacteria
• Food residues
• Organic compounds (including pesticides)
• Bromide compounds (e.g. paints)
• Phthalates (e.g. plasticizers)
• Human dander
• Animal dander and dead animals as well as the excrement of animals

People allergic to dust mites react to the droppings and remains of dust mites, which are found in varying concentrations in house dust and elsewhere in the home.

House dust mites belong to the genus of arachnids. There are about 200 different species of mites. House dust mite allergy is mainly caused by two types of mites:

• the house dust mite
• and the storage mite.

The small arachnids are microscopic. They measure just 0.1 to 0.5 millimeters and can only be seen under a microscope.

The house dust mite can be found anywhere in the home where it can live in direct contact with humans. This is because house dust mites feed primarily on loose human skin scales. Accordingly, the preferred places of residence of house dust mites are:

• Mattresses
• Pillows and blankets
• Cuddly toys

Storage mites are found where food is stored. So in cupboards, pantries as well as in the cellar.
However, the droppings of dust mites and storage mites as well as dead mites can also be found in general house dust as well as in all "dust catchers": curtains, tapestries, carpets, openly stored clothes, open bookshelves.

Dust mites live near people, i.e. in houses and apartments, as well as hotels, etc. They prefer a warm, humid environment with temperatures of 25 degrees and humidity of 65 to 80 percent. The main breeding season of arachnids is between May and October. When indoor spaces are heated and ventilated less frequently in the fall and winter, humidity drops to the point that most animals die. The remains of the mites are then found as a component in house dust.

House dust allergy mainly affects the mucous membranes of the eyes, nose and bronchi but also the skin. The leading symptoms are:

• Eyes: redness, itching, increased tearing.
• Nose: runny nose, stuffy nose
• Bronchial tubes: mucous cough, allergic asthma up to shortness of breath
• Skin: itching, rash, hives with swelling

However, these symptoms are quite non-specific. Above all, they can be confused with the symptoms of a pollen allergy. However, a house dust mite allergy can be distinguished from a pollen allergy relatively easily on the basis of further parameters. For a house dust allergy speaks:

• Symptoms occur throughout the year and not only at certain times of the year.
• Symptoms are stronger indoors than outdoors.
• Symptoms peak in autumn and winter

If sufferers suspect that they are suffering from a house dust allergy, they should not simply resort to over-the-counter remedies sold in pharmacies. To be sure what triggers the symptoms, a clarification should be made by a doctor. The right contact person is always the family doctor. Further treatment is then carried out by a doctor who has additional training in allergology.

• Anamnesis interview: This is the doctor-patient interview. The doctor asks questions about the symptoms, other existing diseases and allergies in the family environment.
• Allergy diary: In order to be able to make an exact diagnosis and, in particular, to distinguish the allergy from pollen allergy, it makes sense to keep an allergy diary. Here the affected person enters every day at which time and in which situations complaints occur.
• Skin allergy test: The skin is lightly scratched and a solution containing the allergens is dribbled on. After a period of exposure, the result is read.
• Provocation test: This test procedure is similar to the skin allergy test. However, in this test method the allergens are applied directly to the nasal mucosa. Since the reactions can be particularly strong here, a test may only be performed under the supervision of a physician (in a doctor's office).
• Blood test: Depending on the type of test procedure, such a blood test provides information as to whether an allergy is present at all or whether there is an allergy to specific substances, for example house dust mites.

The arachnids themselves are harmless to humans. As with all allergies, dust mite allergy is an overreaction of the immune system: the proteins of the dust mites are mistakenly perceived as harmful substances and the immune system then stores this information. With each further contact, the immune system triggers an endogenous defense reaction. Here, histamine is released in large quantities to fight the supposed attacker. The histamine triggers the symptoms described above.

There are several treatment approaches to prevent or reduce the symptoms of dust mite allergy. A number of medications are available over the counter at pharmacies. Nevertheless, those affected should not simply resort to self-medication.

These medications are available for acute treatment:

• Antihistamines: These drugs are available as nasal sprays and tablets. They inhibit the release of histamine, which triggers the allergy symptoms.
• Cortisone / glucocorticoids: Administered as a nasal spray, these drugs cause the nasal mucous membranes to become less swollen. Long-term use should only take place under medical supervision.
• Alpha-sympathomimetics / decongestant nasal spray: These medications provide immediate relief from nasal congestion. However, because of a habituation effect and other side effects, they should only be used for five to a maximum of seven days.
• Leukotriene antagonists: These prescription tablets inhibit messenger substances involved in an inflammatory reaction in the airways. Both allergic rhinitis and asthma symptoms are relieved.
• Mast cell stabilizers/cromones: These drugs inhibit the release of histamine from mast cells. This active ingredient can also be administered as a nasal spray or eye drops.

Through so-called hyposensitization, the immune system can relearn that dust mites are not harmful substances. As a result, the symptoms are significantly alleviated or even disappear completely for one to two years.

• Hyposensitization takes place at the doctor's office. During treatment, the patient receives steadily increasing doses of the allergen. The allergen can either be injected under the skin (subcutaneous immunotherapy) or administered as drops or tablets (sublingual immunotherapy).

Those affected can do a few things themselves to keep their symptoms as low as possible. Basically, all the measures described below are aimed at keeping exposure to the allergen "house dust mite" as low as possible. Not everything can always be implemented in everyday life. But already the conversion of some measures can lead to an improvement of the quality of life.

• Less upholstered furniture, curtains, etc.: House dust mites live in mattresses, upholstered furniture, heavy curtains, cuddly toys, carpets. Therefore, house dust mite allergy sufferers should, if possible, change their living room set to a leather set, avoid carpets and rather use light instead of heavy, dense curtains.
• If upholstered furniture and co - then thorough cleaning (full wash cycle): To keep the population of dust mites in upholstered furniture, carpets and co. low, these should be thoroughly vacuumed very regularly and, wherever possible, washed regularly.
• Precautions when cleaning: To keep allergen exposure low when cleaning, damp mopping is better than using dry dust cloths. Special filter systems can be used when vacuuming. Wearing FFP2 masks can also reduce allergen exposure.
• Alternative mite removal of non-washable items: things such as cuddly toys that cannot be cleaned in a full wash cycle should be frozen for 12 hours and then cleaned in a hand wash cycle.
• Mite-free indoor air: Regular shock ventilation is important, especially in winter when doors and windows are usually closed.
• Reduce mite load in the bedroom: A special mattress cover (encasing) helps to significantly reduce the mite load in the mattress. Beds should be made regularly. In the case of pillows and blankets, make sure that they can be washed on a full cycle. Potted plants in the bedroom increase the room temperature and thus contribute to a climate in which dust mites thrive particularly well.
• Do not use room humidifiers and air conditioners: the reason is that both contribute to a room climate in which mites feel comfortable.

Adherence to preventive measures already significantly reduces exposure to dust mites. In mild cases of house dust allergy this is often already sufficient. In more severe cases, after consultation with the doctor, the medications described above can help. In severe cases, hyposensitization helps. If those affected adhere to this three-stage procedure, the house dust mite allergy is usually well manageable.

Important to know: Many house dust allergy sufferers have a so-called cross allergy to shellfish. It is therefore not advisable to eat them. If left untreated, house dust mite allergy can lead to the so-called floor change. Then an allergic asthma develops, which is a severe health burden.

Selection of vacation rooms; dry skin in old age - apply cream often; make use of help with regular bed-making.

The problem with house dust allergies in seniors is that other underlying diseases often exist in advanced age. This intensifies symptoms, which further reduces the quality of life. The consistent implementation of measures to reduce mite exposure at home is therefore particularly important.

Here are some tips that are particularly important for seniors:

• Skin care: dust mites feed on skin flakes. It is therefore important to apply cream to the skin regularly. This deprives the mites of food. In addition, rough skin is more susceptible to eczema.
• Vacation from the mites: In regions above 1500 meters, as well as in desert climates, there are far fewer mites. So a vacation in these regions is also a break from mite exposure at home.
• Mite-free hotel: There are hotels that advertise mite-free hotel rooms. Otherwise, it is important to put away dust traps (like bedspreads) in the hotel room for the duration of your stay.
• Drug interactions: If medications are already being taken due to pre-existing conditions, care must be taken to determine whether there is a harmful interaction between these and medications for house dust allergy.