Positive food challenges despite negative specific IgE testing

Background Skin prick testing and serum food-specific IgE testing are the most commonly used diagnostic tests in evaluating IgE-mediated food reactions. However, the presence of negative tests can be falsely re-assuring such outcomes do not always exclude allergy. Food challenges are therefore indicated. Double-blind, placebo-controlled food challenge is the gold standard for diagnosis, but in many situations, open food challenges are a more practical alternative.