Food allergy blood or skin tests are just a starting point

Allergy skin tests or blood tests (specific IgE to foods) are commonly used to diagnose food allergies in children, especially those with severe eczema.   However, these results are just a starting point -- oral food challenges in a systematic way are essential to developing a reasonable diet that will not trigger the eczema.  

While a large percentage of young children with moderate to severe atopic dermatitis (eczema) do have one or more food allergy triggers, and will improve with elimination of that food, often they will have several false positive results to other foods on skin testing or blood tests.

A 2011 study in the Journal of Pediatrics confirmed that 84% to 93% of implicated foods did not need to be avoided after oral challenges.  Of the 131 oral food challenges performed, only 11 were positive.

We feel that our job as allergists is not only to tell patients what they need to avoid, but also what is okay to keep in the diet.   It is often unnecessary to severely limit a child's diet, especially if based on the results of serum IgE testing alone!

Fleischer DM, Bock A, Spear GC, et al: Oral food challenges in children with a diagnosis of food allergy. J Pediatrics. 2011;158:578-583.