What Parents Should Know About Child Allergy Testing

What Is Child Allergy Testing?

During child allergy testing, allergens are introduced on the child and the allergic reactions are monitored. Alternately, the blood testing is done to decide for the presence of allergy antibodies i.e. immunoglobulin or IgE. 

The child allergy testing may involve pricking, rubbing, scratching and intradermal injection. The intradermal injection is given into the skin. Intradermal tests are a type of skin test. An allergen such as pollen which the child is suspected to be allergic to is injected into the skin to test the reaction to it.

Intradermal tests are much used to diagnose allergy and to test cellular immunity. The doctor will observe for signs of allergic skin reaction (a raised bump or 'wheal') at the site of the injection. Alternatively, the doctor may test the blood and look for specific antibodies that indicate an allergy to a suspected allergen.

What Types And Methods Of Child Allergy Testing Are There?

Allergy skin tests and blood tests are the most commonly used and trusted types of child allergy testing.

The child allergy testing is normally done using skin testing method which is the most preferred. The procedure for this testing involves dropping a small quantity of allergen at the area where testing is proposed to be done and then pricking/ scratching the skin to facilitate the allergen get inside the skin. This area will be watched for any reaction; any reaction at this area confirms that the child is allergic to that allergen.

As an alternate to this, the allergen is injected under the skin by a method known as intradermal skin test. In this test a number of allergens can be tested at different points on the skin.

The blood test used for child allergy testing is called the RAST (acronym for Radioallergosorbent) test. One of the popular versions of this test is known as the ImmunoCap test. In this method, the blood is marked with radioactive markers and these markers highlight immune antibodies so that levels of IgE antibodies can be measured in response to an allergen.

Who Performs Child Allergy Testing?

Skin allergy tests are performed by Allergists. The allergist is a physician who is first trained in a basic specialty, such as internal medicine or pediatrics, and then completed a second training period, typically two years or longer, in allergic disease diagnosis and treatment. Allergists are specialists who are capable of performing tests and interpreting the reactions which indicate an allergy. The physicians attending to the child will refer for testing to an allergist.

Although RAST testing and other blood tests are performed by an Allergist, the primary care doctors can also order RAST blood testing through your medical facility's laboratory.

When Is Child Allergy Testing Indicated?

There is no age restriction or limit for children to undergo child allergy testing. The American Academy of Pediatrics and the American Academy of Allergy, Asthma, and Immunology have clearly indicated that child’s age is not a barrier for allergy testing and children of any age can undergo a child allergy testing as long as there is a medical necessity.

There is no necessity for all children to go for child allergy testing. Usually, allergy testing will be the last diagnostic tool used by the doctor unless the potential for reaction is severe. Even in cases of severity allergy testing should be taken as a last resort after exhausting other avenues of diagnosis. This is due to the reason that even a small amount of allergen may produce a life-threatening reaction.

The doctors do not go straightaway for child allergic testing since they do not consider this as a first-line diagnostic tool because:

	The results of allergy tests can be false-positive or false-negative
	Positive reactions do not indicate that the child will experience an allergic reaction
	Child allergy testing is likely to cause severe reactions
	As a child outgrows an allergy skin test results can remain positive
	child allergy testing can not be detected for all allergens; even if the child does not show positive on allergy tests the child may still have allergy
	Since blood tests are generalized, it could be misinterpreted to indicate an allergy even though none exists

The doctors normally do not recommend for child allergy testing if the allergy is mild to moderate and if the allergy is well controlled with conventional means. On the contrary the doctor will assist in planning for allergy avoidance and identification. There are situations where allergy test is a must. These are:

	If the child has poorly controlled asthma or allergies
	When there is a need to pinpoint between allergies and illnesses such as colds, flu's, viral infections, sinus infection/trouble, or asthma
	If the child is a candidate for allergy shots and it must be determined what allergens to treat for

The test results of allergy testing should not be taken as a conclusive evidence for allergy; instead, this should be interpreted with other things such as the child's medical history, symptoms, frequency and severity, and a complete, accurate, current medical exam. If all factors point to the fact that the child has allergic tendencies then the doctors and allergists should devise the best course of allergy treatment for your child.