An allergy skin test is the preferred method for pinpointing which allergens are causing an allergic reaction. However, these tests raise special concerns for children who fear needles or who may become alarmed at the raised bumps that generally signal a positive reaction. Parents and healthcare providers must be sensitive to these fears and ready to offer the support necessary to help a child successfully complete testing.

During an allergy skin test, the child's arm or back is marked with an ink pen – each mark corresponds to an allergen. Tiny amounts of the allergen are then introduced to the appropriate spot marked on the child’s skin by one of two methods:

• Epicutaneous testing. The allergen is introduced just barely below the surface of the skin by either a prick, scratch or patch method.
  
  
• Intradermal testing. The allergen is injected below the skin with a needle and syringe.

A period of at least 15 minutes then passes before the child is examined for positive reactions to any of the allergens. If a raised bump (similar to a mosquito bite) appears, it is likely the child is allergic to that allergen.

Although most children do not find allergy testing to be painful, they are likely to feel some discomfort both during and after the process. Itching and redness at the puncture sites are not unusual. Parents should prepare their child for these likely side effects. A cool, wet cloth often can relieve some of the discomfort caused by itching.

For some children, allergy skin tests are not a practical option. This is particularly true for those with certain skin diseases (e.g., eczema, hives). In such cases, a physician might recommend radioallergosorbent (RAST) testing. This blood test detects immunoglobulin E  (IgE) antibodies for particular antigens. Though the test misses some allergies, it is a valuable testing option.

An elimination diet may be recommended when a food allergy is suspected. This diet involves removing suspect foods from a child’s diet to see if allergic reactions persist.

Parents also can contribute to an accurate diagnosis by keeping a diary of their child’s allergy symptoms. The diary should include the following circumstances surrounding the appearance of symptoms:

• Time, date and location
• Foods eaten recently
• Pollen count and mold count
• Recent exposure to animals
• Recent activity (e.g., playing outdoors, visiting a farm)