4 important allergy tests: Skin prick, skin pressure, serum, drug challenge

For people with atopic allergies, allergic reactions often cause discomfort, affecting life, work, and in some cases even affecting the health and life of the patient. Let's find out some tests with Vinmec to help detect allergy risk factors early and help prevent allergies effectively.

Allergies are a common response of the immune system to protect the body against foreign allergens. Common allergens include:
Airborne agents: house mites, pet dander, mold, pollen... Food: seafood, eggs, milk, red meat (protein)... Antibiotics and some other drugs. However, overreaction can cause organ damage, organ dysfunction or worse, anaphylaxis. To avoid health risks, people with allergies can perform a number of tests to find out the allergenic agent, thereby suggesting appropriate treatment.

Skin prick test is a method of evaluating allergies by inserting an allergen into the epidermis of the patient's skin, to determine the state of the immune system's response to that allergen.
Skin prick test is often indicated to identify allergens in diseases: allergic rhinitis, asthma, atopic dermatitis (eczema), drug allergy, food allergy...
Procedure
Before performing the skin prick test, the patient should note:
Stop taking the H1 receptor antagonist for at least 5 days. Stop taking corticosteroids (high-dose, long-term) for at least 3 days. Stop taking tricyclic antidepressants for at least 3 weeks. Stop applying corticosteroids or Calcineurin inhibitor to the area to be tested for at least 7 days. Conduct at least 4 weeks after UV therapy in the area to be tested. Skin prick test results show:
If the patient's body produces IgE antibodies against the tested allergen, the needle puncture site will appear a papule on an erythematous background. The specialist will measure the size of the papule and determine the degree of allergy positive.

Skin test is a method of allergy testing by placing an allergen on the surface of the patient's skin, keeping it in place for a period of at least 48 hours to determine the degree of late hypersensitivity to the allergen. there.
Purpose of the skin test To accurately determine the causative agent of contact dermatitis. Usually chemicals found in cosmetics, metalwork, leather goods, rubber and many other materials. Diagnosis of late suspected allergic conditions, especially drug-induced: generalized pustular rash, erythema multiforme, eosinophilic drug reaction syndrome (DRESS), toxic epidermal necrolysis (TEN). Procedure Before performing the skin test, the patient should note:
Stop taking corticosteroids (high dose, prolonged) at least 3 days. Stop taking tricyclic antidepressants for at least 3 weeks. Stop applying corticosteroids or Calcineurin inhibitor to the area to be tested for at least 7 days. Conduct at least 4 weeks after UV therapy in the area to be tested. Allergens will be placed in test dishes and applied to the patient's skin (usually on the back) for 48 hours. The doctor will then take the test results and read the results for the first time after 20 minutes to see if there is any reaction to the test substance. In order to avoid missing the case that the skin has a slow reaction to the test substance, the patient will need to check again after about 2 days.

Serum testing is a method of allergy testing by intradermal injection, the purpose of which is to determine the status of chronic idiopathic urticaria.
Autologous serum skin test (ASST) is usually indicated in cases of urticaria lasting more than 6 weeks with no known cause.
Before performing the serological test, the patient should stop taking Histamine H1 receptor antagonists for at least 3 days.

Drug challenge test is a method of allergy testing by introducing drugs with appropriate doses (from low to high) into the patient's body by natural route.
Purpose of the drug challenge test Exclude unknown drug allergic reactions. Check the safety level of some drugs that patients are worried about using. Exclude cross-reactivity between drugs of the same class. Identify drug allergy when other testing methods fail. Procedure Before performing the drug challenge test, the patient should:
Stop taking the H1 receptor antagonist for at least 5 days. Stop taking corticosteroids (high-dose, long-term) for at least 1 week. Stop taking tricyclic antidepressants for at least 5 days. Discontinue beta-blockers and ACE inhibitors for at least 1 day. After that, the drug is introduced into the patient's body in a natural way from low to high doses, with a minimum interval of 30 minutes between dose increases.
To find out the source of the disease, as soon as there are signs of an allergy, the patient needs to go to a reputable hospital to be examined by a specialist doctor and conduct specific tests. Currently, Vinmec International General Hospital is one of the leading prestigious hospitals in the country, trusted by a large number of patients for medical examination and treatment. Not only having a modern physical system and equipment, Vinmec is also a place to gather a team of experienced doctors and nurses who will greatly assist in the diagnosis and early detection of abnormal signs of cancer. patient's body. In particular, with a space designed according to 5-star hotel standards, Vinmec ensures to bring the patient the most comfort, friendliness and peace of mind.