Allergy to house dust is one of the most common problems faced by modern residents of megacities. Often people spend years treating a chronic runny nose or cough, not suspecting that the source of their ailment is the microscopic inhabitants of mattresses and carpets. Laboratory Invitro offers highly accurate diagnostic methods to identify sensitization to allergens of mites of the genus Dermatophagoides.
Timely consultation with a doctor and testing allows you not only to relieve symptoms, but to understand the root cause of the disease. In this article, we will look in detail at how to properly prepare for the test, what the numbers on the results form mean, and what steps to take if the diagnosis is confirmed.
It is important to understand that house dust is a complex cocktail of particles of skin, animal hair, mold spores and waste products of microfauna. It is the proteins contained in tick excrement that most often cause a violent reaction of the immune system. Laboratory tests help separate true allergies from other respiratory diseases.
What are house dust mites
House dust mites are tiny, arachnid-like creatures that are invisible to the naked eye. They feed on exfoliated scales of human skin, so bedding, upholstered furniture and carpeting are ideal habitats for them. The main culprits of allergies are considered to be two types: Dermatophagoides pteronyssinus and Dermatophagoides farinae.
The allergenic activity of these microorganisms is not associated with their bites, since they do not bite humans, but with their excrement. One gram of house dust from a mattress can contain up to 15,000 mites. Their waste products contain powerful enzymes, which, when inhaled, settle on the mucous membrane of the respiratory tract and cause immune response.
⚠️ Attention: House dust mites do not live on human skin and are not transmitted from person to person like infectious diseases. They live exclusively in the environment of your home.
The reproduction of these arthropods is facilitated by high humidity (more than 60%) and air temperature of about 20-25 degrees Celsius. That is why the peak of allergy exacerbations often occurs during the heating season, when the air in apartments becomes dry, but warmth and moisture remain in the beds.
To reduce the concentration of mites in the bedroom, maintain air humidity below 50% and regularly ventilate the room, taking pillows and blankets out of the cold or direct sunlight.
Symptoms of dust mite allergy
The clinical picture of an allergy to house dust often resembles the symptoms of a cold or ARVI, which leads to incorrect diagnosis. Patients may take antibiotics for years for “persistent bronchitis,” when in fact they have year-round allergic rhinitis. The key difference is the absence of an increase in body temperature and a characteristic seasonality or connection with stay in certain rooms.
The most common manifestations of sensitization to Dermatophagoides mites include:
- 🤧 Constant nasal congestion, worsening in a horizontal position or when cleaning.
- 👁️ Redness of the eyes, lacrimation and itching of the eyelids that do not go away after washing.
- 🤧 Frequent sneezing, especially in the morning or after sleep.
- 🌬️ Dry cough or asthma attacks that occur in dusty rooms.
In children, symptoms may be more severe and include skin manifestations such as atopic dermatitis. Allergic reaction may develop immediately after contact with the allergen or be delayed, appearing after a few hours. This makes it difficult to identify the trigger yourself without laboratory tests.
If you notice that your symptoms worsen after sleeping, spending time in the library, working with archival documents, or playing with stuffed animals, the likelihood of a dust mite allergy is extremely high. In such cases, it is necessary to take a blood test for specific immunoglobulins.
Preparing for the analysis at Invitro
Laboratory Invitro conducts blood serum tests for the presence of specific IgE antibodies. This method is considered the “gold standard” for diagnosis, as it is safe, has no contraindications and does not require discontinuation of antihistamines, unlike skin tests. However, to obtain the most reliable result, it is still worth preparing for the procedure.
Blood is donated in the morning on an empty stomach. At least 8-12 hours should pass between the last meal and the collection of biomaterial. You can drink clean still water. On the eve of the test, it is recommended to exclude fatty foods, alcohol from the diet and avoid heavy physical activity, as this can affect the biochemical parameters of the blood, although the IgE level has little effect.
An important advantage of the method is the ability to donate blood even during an exacerbation of the disease. If you are taking hormonal medications or undergoing immunotherapy (ASIT), be sure to tell your doctor about this before sending you for testing. Medical worker will take these factors into account when interpreting the data.
☑️ Checklist before going to the laboratory
Clothes for visiting the laboratory should be comfortable, with sleeves that can be easily rolled up. If you are prone to fainting or have low hemoglobin, bring sweet tea or chocolate with you to eat immediately after the procedure.
Interpretation of results and norms of indicators
The result of the analysis in Invitro usually presented as a quantitative value of the concentration of specific IgE antibodies in international units (IU/ml or kU/L). Reference values may vary slightly depending on the analyzer used, but the overall gradation remains the same. The presence of IgE class antibodies indicates sensitization of the body to this allergen.
Below is a table for classifying specific IgE levels:
| Class | IgE concentration (kU/l) | Antibody level | Interpretation |
|---|---|---|---|
| 0 | < 0.35 | Negative | No allergies identified |
| 1 | 0.35 – 0.70 | Doubtful | Retest or follow-up required |
| 2 | 0.70 – 3.50 | Positive (low) | There is sensitization, symptoms are possible |
| 3 | 3.50 – 17.50 | Positive (medium) | Severe allergies |
| 4-6 | > 17.50 | Positive (high) | Acute allergic reaction |
It is important to understand that a positive test result (the presence of antibodies) does not always mean the presence of clinical symptoms. This condition is called sensitization. A person can have high titers of IgE to house dust mites, but not experience discomfort. However, with a combination of a high indicator and characteristic symptoms, the diagnosis of “allergy” is considered confirmed.
⚠️ Attention: Only an allergist should interpret the results. Self-treatment based on numbers from the form may lead to ineffective therapy or worsening of the condition.
Sometimes on the form you can find the note “total IgE”. This indicator gives a general idea of the allergic mood of the body, but does not indicate a specific allergen. To accurately diagnose house dust mites, you need specific IgE to Dermatophagoides pteronyssinus (d1) and farinae (d2).
Why may results vary between laboratories?
Different laboratories may use different test systems and calibrators. Therefore, it is best to compare the dynamics of treatment by taking tests in the same network, for example, in Invitro, in order to minimize equipment error.
Methods for controlling house dust mites
If the analysis confirms the presence of an allergy, the main method of treatment becomes elimination of the allergen, that is, the creation of conditions unsuitable for mites to live. It is impossible to completely get rid of them in an apartment, but you can significantly reduce their concentration to a safe level.
The first step should be to replace the bedding. Duvets and feather pillows are ideal breeding grounds for mites. They should be replaced with synthetic analogues with tightly woven fabrics that can be washed at a temperature of at least 60 degrees. Exactly high temperature kills mites and destroys their allergens.
The second important aspect is humidity control. The use of humidifiers in the bedroom if you are allergic to mites is contraindicated if the humidity exceeds 50%. Instead, the use of dehumidifiers or air conditioners may be required. Regular wet cleaning with the addition of acaricidal agents (killing mites) is also required.
- 🧹 Use vacuum cleaners with HEPA filters so that the blown air does not carry allergens back.
- 🛏️ Wash your bed linen once a week at 60°C or higher.
- 🌡️ Ventilate the room daily, including in winter, as ticks do not tolerate low temperatures and drafts well.
- 🚫 Remove carpets, soft toys and excess textile furniture from the bedroom.
Reducing air humidity below 50% is the most effective non-drug way to control the house dust mite population.
Modern methods of treating allergies
Drug therapy is prescribed by a doctor to relieve symptoms. This usually includes second- and third-generation antihistamines, corticosteroid nasal sprays, and vasoconstrictor drops (short-term). These remedies make life easier for the patient, but do not eliminate the cause of the disease.
The most effective treatment method to achieve long-term remission or complete recovery is allergen-specific immunotherapy (ASIT). The essence of the method is the gradual introduction of microdoses of the allergen into the body, which “trains” the immune system not to react violently to it. B Invitro and other clinics may offer various forms of ASIT: injection or sublingual (drops/tablets under the tongue).
The course of treatment usually lasts from 3 to 5 years. This requires discipline from the patient, but the result is worth it: after the end of therapy, the person can calmly come into contact with the allergen without developing a reaction. It is important to start ASIT during remission, when symptoms are minimal or absent.
Do not neglect the auxiliary means. Rinsing the nose with saline solutions (irrigation) mechanically removes allergens from the mucous membrane, reducing inflammation. Using barrier sprays that create a protective film in the nose can also be an effective preventative before leaving the house or cleaning.
When choosing antihistamines, pay attention to their generation: newer generation drugs (for example, based on cetirizine or loratadine) are less likely to cause drowsiness and do not affect concentration.
Frequently asked questions (FAQ)
Can I get tested for allergies while taking antihistamines?
Yes, you can. Unlike skin tests, a blood test for specific IgE (which is carried out in Invitro) does not require discontinuation of antihistamines. They do not affect the level of antibodies in the blood. However, you should tell your doctor if you are taking any medications.
What is the difference between Dermatophagoides pteronyssinus and farinae mites?
These are the two main types of dust mites. They have a similar antigenic structure, so they often cause a cross-reaction. In tests they are often tested together or a mixture of allergens is used. They live in the same conditions and the methods of dealing with them are identical.
How often should you get tested for allergies?
The frequency of testing is determined by the doctor. Typically, a repeat test is taken to assess the effectiveness of treatment (for example, after a course of ASIT) or if the clinical picture has changed. Sensitization is a fairly stable condition, so taking a test “for prevention” every month does not make sense.
Does quartzing a lamp help against ticks?
Quartzization (UV irradiation) effectively kills bacteria and viruses in the air and on surfaces, but it has little effect on house dust mites. Mites hide deep in the fibers of the fabric, where ultraviolet radiation does not penetrate. The main weapons against them are temperatures above 60°C, freezing or chemical acaricides.
Can a mite allergy go away on its own with age?
In children, allergies can sometimes “outgrow” with age, but in adults this rarely happens. Without treatment and elimination of the allergen, the disease often progresses, moving from rhinitis to bronchial asthma. Therefore, it is dangerous to ignore the problem.