House dust allergy test
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Dust mite allergy belongs to the class of IgE-mediated allergy. If you are allergic, their immune system overreacts to an allergen by producing antibodies called Immunoglobulin E (IgE). These antibodies bind to cells that trigger release of chemicals, causing an allergic reaction.
Three common allergy diagnostic tests are available to help confirm the causative allergen, differentiate allergic disorders from other diseases, uncover previously unsuspected allergen and guide the disease management. These tests are applicable to both dust mites and other IgE-mediated allergies.
It must be stressed that allergy test results cannot be used on their own to confirm allergy. Many patients are sensitive to the allergen, but show no clinical symptoms (i.e. have sub-clinical allergy). Hence, the sIgE result must be considered with your clinical history, environmental factors, your life style and habits. Before a test, the doctor first goes through the observed symptoms with the patient. A thorough medical history is the basis for every subsequent test. A general distinction is made between skin tests , blood tests and provocation tests .
Skin prick test
The prick test is used most often, also when testing for a mite allergy. The patient receives various test solutions with potential allergens, including mite allergens, on the forearm. The area with the test solution is then pierced very briefly with a fine lancet so that the solution can penetrate the skin. After about 15 to 20 minutes, a reaction is now checked. If a skin reaction, such as a wheal or reddening or the like, shows up at the corresponding point, then this speaks for an allergy. It must be noted that you should NOT take antihistamines before the test, as they can interfere with the results. Again, the pure test result is only of limited significance. A thorough review of medical history with a doctor is very important. If suggested by the doctor, other tests such as a blood test or a provocation test would be useful to cross-check the positivity of a specific house dust mite allergy.
Specific IgE test on blood is a blood test that detects circulating IgE produced against the causative allergen. Based on your clinical history, your doctor will choose which allergens to be tested. In the blood test, just a few drops of blood are enough to test them for antibodies against individual allergens (specific IgE ). If, for example, such antibodies against allergens of the house dust mite are found in the blood to a high degree, then this indicates a house dust allergy is highly likely. Again, the results must be confirmed with medical history, the observed symptoms and possibly another test.
Multi-array based specific IgE test on blood combines biochip technology and purified natural and recombinant allergen components in a miniaturized assay. It allows simultaneous measurement of total IgE (tIgE) and specific IgE (sIgE) against a plethora of allergen extracts and molecular allergens. Based on test panels composition of allergen extracts and molecular allergens, a near complete picture of each patient’s sensitization status is obtained. The newest version can detect more than 290 specific and cross-reactive allergen components in a single run, which allows the detection of specific markers for HDM and SM, egg, milks, seafoods, nuts, cereals, legumes, fruits, vegetables, meats, pollens, animal dander, moulds, and insects. Result can be available for doctor’s review in 4 to 6 working days.
The provocation test is usually not the first test to be carried out because it also carries most of the risks of the allergy tests presented here. In the provocation test, the patient comes into direct contact with the allergen. In the case of a suspected house dust mite allergy, a house dust mite allergen extract would be brought into contact with the mucous membrane, for example via the nose. The dose of the extract is gradually increased until a reaction, i.e. the typical house dust allergy symptoms , appears. Before this step, the doctor would first use a harmless saline solution to test whether the mucous membrane is generally hypersensitive. If it is not, but there is a reaction with the house dust mite allergen extract, then there is a lot to be said for a corresponding allergy.
Prevention is often enough in the case of a mite allergy. Although mites cannot be completely banished from the house, some measures can greatly reduce their number. With special protective covers ( encasing ) for mattresses, pillows, duvets and the like, you remove part of the food source from the mites, and the mite droppings remain enclosed. In addition, pillows, blankets and covers should be washed regularly.