House dust allergy

1. Around 4000 dust mites can be detected in one gram of bed dust.

2. Two grams of skin flakes are enough to feed up to 1.5 million dust mites.

3. They find ideal conditions at a room temperature of 25 degrees Celsius and a humidity of 70 percent.

4. Heating air makes the air in the apartment drier and a large proportion of the mites die.

5.A female dust mite lays up to 300 eggs during its lifetime. The life span of an animal is between three and four months.

6. In children and adolescents, house dust allergy is the second most common allergy after grass allergy.

7. In Germany, about seven percent of the population suffers from a year-round house dust mite allergy.

^{Sources: Planet Knowledge, Allergy Information Service}

House dust is made up of many different materials that accumulate in our homes over time. From room to room, its composition varies, but as a rule, its components include hair and skin flakes, lint from clothing or upholstered furniture, plant parts such as leaves, pollen or pollen, and tiny particles of rock.

In addition, mineral fibers, fungal spores or various germs can also be found in the dust. All these components can have effects on our body, but are not solely responsible for the sneezing cascades and shortness of breath in house dust allergy sufferers. The reason for this is the mite, which is found mainly in the dust of bedrooms and can also be detected on various textiles and upholstered furniture in the living area.

Taken precisely, the colloquially used term of "house dust allergy" is misleading. Therefore, we speak in the following of the "house dust mite allergy".

House dust mites (lat. dermatophagoides) belong to the genus of arachnids. They grow to a size of only 0.1 to 0.5 mm and are of very low weight. They feel particularly comfortable at temperatures of 20-30 °C and a humidity of 60-80 %. Since similar conditions often prevail in our bedrooms, the small, actually harmless, little animals prefer especially the vicinity of our bed or even the bed itself.

Who now thinks that the accumulation of mites testifies to a lack of hygiene, is mistaken: because regardless of the respective state of cleanliness mites are present in every household.

Mite feeds on dead skin scales, of which we humans lose on average about 2 grams daily. This amount is enough to feed over 1 million of the tiny arachnids for 24 hours.

However, despite the constant supply of dead skin cells, the mite population is subject to seasonal fluctuations.

While it multiplies most in the period from May to October due to favorable external conditions, the major die-off occurs with the onset of the colder season and the heating season. But although most mites fall victim to the dry indoor air, the burden on allergy sufferers still seems to be increasing.

This is due to the fact that the allergenic component is not found in the body of the mite, but in its excretions. The allergen consists of a protein-containing compound that, although actually harmless, is classified as dangerous by our bodies.

Mite excrement is so tiny that it can only be detected under a microscope. Due to their highly porous structure, they disintegrate into many individual parts when dried and disperse with normal house dust throughout the room as well as in adjacent rooms. Although most mites die with the beginning of the heating season, their excretions, the actual allergens, remain over the fall and winter.

Because the excretions have a very low weight, they get with the beginning of the cold season through heating into the air we breathe and are easily inhaled in this way. This can have various consequences.

People who are allergic to dust mites show allergy symptoms throughout the year. These often occur especially at night, when the body should actually come to rest. The restless and interrupted sleep behavior often makes the allergy sufferer wake up in the morning "ravaged" and can have an impact on his performance.

Symptoms include:

• swollen nasal mucous membranes
• stuffy nose or, in rarer cases, runny nose
• severe sneezing
• watery, itchy or red eyes
• persistent dry cough to shortness of breath
• rarely: Headaches, sleep disturbances and impaired performance
• Neurodermatitis (atopic eczema)

Do you experience several of these symptoms, especially in the morning after getting up, over a longer period of time or outside the pollen season? Then you should visit your doctor to clarify whether you may suffer from a dust mite allergy.

Despite the harmless-sounding name, you should not take the allergy lightly. Because a dust mite allergy can lead, for example, to allergic asthma (med. asthma bronchiale). In this case, a so-called "floor change" takes place: the symptoms then shift to a lower level, in this case from the nasopharynx to the area of lungs and bronchi.

To relieve symptoms, anti-allergic products such as:

• Eye drops such as Pollicrom® eye drops 
• Nasal spray such as Pollicrom® nasal spray 
• Antihistamine tablets

To achieve permanent symptom freedom, there is still the possibility of hypo- or desensitization. Attempting to influence the mite population and their excretions through certain behaviors can also lead to relief from allergy exposure.