When does a child with eczema need allergy testing?

If your child has eczema, you may feel that the flares would stop if only you could find what causes them. Many parents ask about allergy testing.

Here’s what dermatologists tell parents about eczema and allergy testing.

Allergy testing

Some, but not all, children who have eczema benefit from allergy testing.

Not every child with eczema needs allergy testing

This is true because:

1. Doing only one thing like avoiding allergens (what causes an allergic reaction), won’t clear eczema.

2. The most effective way to clear eczema is to follow an eczema management plan.

   This plan includes giving your child baths, applying moisturizer, using your child’s eczema medicine (when needed), finding your child’s eczema triggers, and helping your child avoid individual eczema triggers. Triggers differ from allergens.

3. Allergy shots have not proven helpful for eczema. There is one exception. Shots that treat lung allergies may reduce eczema.

3 signs you should talk with your child’s dermatologist about allergy testing

If you notice any of the following, you should ask your dermatologist about allergy testing for your child:

1. You’ve been following the eczema management plan, which your child’s dermatologist created, for a few weeks. Despite sticking to the plan, your child’s eczema:

• Remains the same
• Improves slightly

2. Your child’s eczema flares every time you feed your child certain food(s). To avoid other health problems, you should remove foods from your child’s diet:

• ONLY when your child has a severe or immediate reaction to a food or beverage
• After talking with your child’s dermatologist if the reaction is not severe.

3. Your child is not growing as expected.

What happens during an allergy test?

Different types of allergy tests are used. Here’s what happens during each:

Skin prick test: During this test, small amounts of substances to which your child may be allergic will be placed on your child’s skin. Usually, the substances are placed on the forearm or back. Next, the skin is scratched or pricked. The skin is checked for a reaction at specific times.

Patch test: Substances to which your child may be allergic are applied to discs. The discs are then taped to your child’s skin without eczema, usually on the back. Each disc contains a different allergen (substance that can cause an allergy). Your child’s skin be will checked at specific times for reactions.

Food allergy testing: A skin prick test or blood test can tell you what food allergies your child does not have.

If your child has a positive reaction to a food during one of these tests, the results must be confirmed with another type of test. Your child’s dermatologist or allergist may refer to this type of type of test as a food challenge.

There are different types of food challenges. If this test is right for your child, the dermatologist or allergist can tell you what to expect.

Related AAD resources

• Can some products cure eczema?

• Do certain foods cause eczema flares?

• How do dermatologists control eczema?

References
Sidbury, R. “What’s new in atopic dermatitis research?” (2014, August). In Lio PA (Chair), “What's boiling over: Atopic dermatitis and other eczematous conditions.” Forum presented at the Summer Academy Meeting of the American Academy of Dermatology, Chicago, IL.

Sidbury R, Tom WL, et al. “Part 4: Guidelines of care for the management of atopic dermatitis. Part 4: Prevention of disease flares and use of adjunctive therapies and approaches. J Am Acad Dermatol. 2014 Dec: 71(1);1218-33.

Simpson, EL. “Comorbidity in atopic dermatitis.” Curr Dermatol Rep. 2012 Mar:1(1);29-38.