Cross-reactivity syndromes in food allergy.

The immunological phenomenon of cross-reactivity has consequences for the diagnosis and treatment of certain food allergies. Once allergy to a particular food has been confirmed, positive test results are often obtained against other foods and, although less frequently, true clinical cross-reactivity is determined. This article reviews the relevant clinical aspects of food allergies in which the underlying mechanism is cross-reactivity between foods that are both related and unrelated taxonomically.