Understanding Paediatric Allergy Testing

Allergies in children are increasingly common. These are reactions caused by an overactive immune system, which starts to fight against normally harmless substances, also known as allergens. These allergic reactions can affect different body organs and may lead to severe conditions like asthma, eczema, or hay fever.
Identifying the specific triggers or the allergens responsible for these reactions is the crucial first step towards effectively managing allergies in children.

This article overviews paediatric allergy and the different types of allergy testing in children.

What is Paediatric Allergy?

Paediatric allergy refers to the allergic reactions in children when their immune system responds abnormally to typically harmless allergens such as pollen, animal dander, certain foods, or dust mites. The immune system perceives these allergens as a potential threat and releases an Immunoglobulin E (IgE) antibody.
This immune response also causes the release of chemicals, like histamine, which results in symptoms such as sneezing, itchy eyes, hives, swelling, upset stomach, or even more severe reactions like anaphylaxis.

What are the Types of Paediatric Allergy Testing?

Paediatric allergy testing helps identify specific allergens causing symptoms in children. The main types of allergy tests used in children are:

1. Skin Test
   This skin allergy test is performed to identify allergies to substances like pollen, dust, mould, animal dander, and certain foods and medications. Skin tests can be done in three ways:

• Skin prick test: In this test, a drop of a specific allergen is placed on the skin, which is pricked with a needle to let some of the allergen get inside the skin. If the child is allergic to this allergen, a raised bump with a ring will form in the area.
• Patch test: In patch tests, allergens are applied to patches placed on the skin for 48 hours, mainly to test for delayed skin reactions. The test is done if the child has rashes or hives on the skin to determine which allergen is causing it.
• Intradermal test: This skin allergy test involves injecting the allergen under the skin of the arm of the child. It is mainly used to test for insect venom or penicillin allergies.

2. Blood Test
   A blood test measures the presence of IgE antibodies in the blood produced when the immune system identifies a substance as a threat. This IgE allergy test is done when a skin test is not possible and is mainly of two types.

• Total IgE test: This test measures the amount of IgE antibodies in the blood but doesn’t detect the specific allergen the body is allergic to. The higher the amount of IgE, the higher the chances of an allergy.
• Specific IgE test: It measures how much IgE the child’s body makes in response to a specific allergen. This IgE allergy test is used for allergies caused by pollen, dust mites, mould, certain foods and medicines, and animal furs.

3. Food Challenge Test
   Food challenge test is mainly used to diagnose food allergies when the results of a skin test or a blood test are inconclusive. This food allergy test helps determine whether a child is truly allergic to a specific food, has outgrown a previous allergy, or can safely consume a food that has caused concern before.

The child is given a minimal amount of the suspected food allergen. If no symptoms appear after a waiting period of 10-20 minutes, the dose is gradually increased in steps, with careful monitoring. This process continues until the child has consumed a full serving or until symptoms develop.

Elimination diet is also a food allergy test in which a specific food is eliminated from the child’s diet that may be suspected of causing an allergic reaction. The eliminated foods are then slowly reintroduced one at a time under medical supervision, and the child is monitored for return of symptoms.

4. Drug Allergy Test
   Drug allergy refers to adverse reactions in children to certain types of medicines, like antibiotics, nonsteroidal anti-inflammatory drugs (NSAIDs), or vaccines. The drug allergy test may involve a drug provocation test, where the child is given gradually increasing doses of the suspected drug under close medical supervision. Other ways to determine a drug allergy in children is by doing a blood or skin test.

Paediatric allergies are common and often manageable with the proper care. It’s essential for parents to recognise symptoms and consult a healthcare provider for accurate diagnosis to keep their child safe and healthy.
If parents suspect their child has an allergy, they must contact a doctor and schedule an allergy test with Dr Lal PathLabs.
To learn more, download the Dr Lal PathLabs app now.

FAQs

1. What is allergy test?
   An allergy test identifies substances that may cause an allergic reaction through skin, blood, drug, or food allergy tests.
2. What are different allergy types?
   Some common allergy types include food allergies, respiratory allergies, skin allergies, insect sting allergies, and drug allergies.
3. What is Type 2 hypersensitivity?
   Type 2 hypersensitivity is an immune reaction where IgG antibodies mistakenly target harmless substances and destroy the body’s healthy cells.