Allergy diagnostic tests

Allergic - immune diseases, if not diagnosed and treated promptly, will affect quality of life such as poor concentration, reduced work productivity...

Allergy is a pathological condition of an immune response to an allergen that leads to tissue damage and dysfunction of some organs.
With the life of industrialization and modernization, people have produced and invented a lot of equipment, chemical materials to serve human life and vice versa, some chemicals or waste products. Products released by the industrial process have caused many harms to humans, one of which is allergies to various allergens. These allergens can be feathers, chemicals, foods, vegetables, meat, animal and vegetable proteins, drugs, etc. Some other agents also cause other allergic diseases such as fungi. , parasites, bacteria, protozoa, ....

However, clinical reality shows that the majority of patients who come to medical facilities present with very diverse symptoms, which can be chronic or acute urticaria, which can manifest as mild to severe allergic reactions. serious, even deadly. A special thing, currently, most people when they have itching, allergies and urticaria treated at a dermatology specialist, they immediately think of helminths and immediately switch to specialist examination and testing. Parasitology might find a better disease.
An allergen is a substance that can cause allergic reactions. The allergen in some people may view it as a foreign body or dangerous substance but do not react against it. It could be a foreign object or a substance that is dangerous to one person but not to another - that is, an allergic reaction depends on each person's body.
So when encountering a foreign object, the body will have protective reactions. However, if the reaction occurs excessively, causing abnormalities in the body, it is called an allergic reaction or more severe, can lead to death, is called anaphylaxis.
Allergies can cause:
Allergic rhinitis : Nasal congestion; Itching, runny nose; Itchy, runny or swollen eyes (conjunctivitis). Atopic dermatitis , an allergic skin reaction also known as eczema, can cause: Itchy skin; Redness of the skin; Peeling or peeling of the skin Food allergies can cause: Itchy mouth; swelling of the lips, tongue, face or throat; Hives; Anaphylaxis... Allergies to insect stings can cause: A large area of ​​swelling in the area where the skin was stung; Itching or rash on the body; Cough, chest tightness, wheezing or trouble breathing; Anaphylaxis... Allergies to the drug can cause: Urticaria; Itchy skin; Rash; Facial swelling; Wheeze; Anaphylaxis...

Allergy testing is indicated when there are signs or symptoms suggestive of an allergy to one or more substances. Allergy signs and symptoms may include: rash, dermatitis, eczema, red eyes, itching, cough, stuffy nose, sneezing, asthma, abdominal pain, trouble breathing, nausea, vomiting, diarrhea.

Skin prick test is a test method to clinically determine the body's sensitivity to an allergen, by introducing one or more allergens into the skin, then evaluating the size and characteristics of the nodule. edema and local inflammatory reaction. Allergy skin testing is a medical diagnostic method for the diagnosis of allergic diseases, detecting a small mark on the surface of the skin to see a response after a skin prick. Prick test or scratch test: It is pricking the skin with a small needle containing a small amount of allergen used in preparation for testing. There are two possible types of this allergen test:
Prick test or scratch test : a skin prick with a fine needle containing an antigen used for testing; Patch test: also known as the application test used to stick on the surface of the skin and on the patch containing the allergen. If an immune response is seen resulting in redness, urticaria or, worse, anaphylaxis, it can be concluded that the patient is sensitive to the tested allergen. Further tests may be performed to determine the causative agent of the allergen. The "scratch test" as its name suggests is a common type of test for allergen detection.
This test helps the doctor diagnose the allergen with the pathology: asthma, allergic rhinitis, atopic dermatitis (eczema), food allergies, drugs. It is important to note that before doing the skin prick test, the patient must stop taking antihistamines at least 5 days before the test.
Some allergen test kits are related to the detection of allergens or foreign substances related to the respiratory tract, food.

2.2 Allergy Panel Test Through this allergy test, the patient has the opportunity to identify 60 to 107 of the most common allergens on a single test sample including: House dust, dust mites, cat hair, dog hair, sesame, pollen, insects, animals, meat, fish, shrimp, crabs, squid, eggs, milk, grains, vegetables, fruits, seeds or other causes.
Quantitative testing for specific IgEs is now widely prescribed by specialists in many cases such as:
Patients with signs or symptoms suggestive of an allergy to one or more substances. Signs and symptoms of an allergy may include: Rash, hives, dermatitis, red itchy eyes, stuffy nose, sneezing, itchy skin-eyes-nose-throat symptoms, or severe-acute symptoms such as difficulty breathing. breathing, abdominal pain, loose stools. Patients with chronic allergies but have not discovered the cause: This test can help orient the causes that we are exposed to every day. Allergy panel test is done through a blood draw at any time of the day, not affected by eating, so patients can come to check at any time.
Thus, with just 1 test of Allergy Panel, it is easy to accurately identify hundreds of allergens that are the cause of allergic diseases in people with acute or chronic allergic symptoms. From there, the doctor will have the correct treatment direction for the patient, and at the same time advise the patient to correctly avoid the allergen.
2.3 Serum test A method of using a patient's own serum to be injected into the patient's skin. The purpose of this test is to identify chronic idiopathic urticaria. ASST is indicated in cases of urticaria lasting more than 6 weeks with no known cause.
Pre-test notes: Discontinue histamine H1-receptor antagonists at least 3 days prior to testing.

2.4 Drug challenge test This is a test where controlled doses of drugs (from low to high) are injected into the patient's body by natural drug route. The drug is introduced into the patient's body according to the natural route of administration, in low to high doses. The interval between dose increments should be at least 30 minutes. For a challenge test to find a safe drug, it is necessary to proceed to the usual dose of the drug.
Notes before performing a drug challenge test :
Discontinue histamine H1 receptor antagonists for at least 5 days. Discontinue oral corticosteroids (high-dose, prolonged) for at least 1 week Discontinue tricyclic antidepressants for at least 5 days. Discontinue beta-blockers and ACE inhibitors for at least 1 day. This method helps to rule out unclear drug allergies, confirm the safety of certain drugs that are worried patients when taking them, rule out cross-reactions between drugs of the same class, determine the patient's condition. drug allergy when other methods are negative or fail.
Allergic pathology is not easy to diagnose the cause of the disease. When going to the allergy clinic, the patient should bring drugs, foods or suspected allergens to serve the diagnostic process.
At Vinmec International General Hospital, there is a package of examination and advice on treatment of atopic dermatitis for all customers of all ages. Customers at risk such as allergies, affected by ambient conditions such as weather, climate, humidity, ... will be examined and tested including:
Specialist examination Dermatology Perform tests such as: quantification of IgE, fresh mycobacteria, specific IgE for respiratory and food allergens (Panel 1 Viet), Rida Allergy Screen test (panel 1). ..