Adverse reactions to food are a common occurrence in clinical practice. Some of these reactions are “true food allergies” while others represent various forms of “food intolerance”, or toxicity.

There has been a real increase in true food allergies, e.g. peanut allergy, which has accompanied the general increase in allergic diseases worldwide. In practice, however, more frequently doctors encounter patients with “atypical” or delayed adverse reactions to food which, are not Type I IgE dependent reactions, and in whom conventional allergy tests are usually unhelpful. The identification of the triggers of such reactions requires careful history taking and in some cases can be confirmed by new tests. The corner stone of the management of food allergies is identification and avoidance. No commercial immunotherapy vaccines are available for clinical use for food allergy.

It is important to take care with influenza or yellow fever vaccinations in egg allergy subjects. MMR by contrast, may be safely administered to egg allergic subjects for the future, novel genetically engineered proteins have a real potential for allergenicity.