[Egg allergy]

Egg is one of the most important allergen in childhood feeding. The pathogenic mechanism in egg allergy is immediate, type I, IgE-mediated hypersensitivity, although other mechanisms are possible. The aim of this review is to point out that diagnosis of egg protein allergy is mainly clinical and double-blind placebo-controlled food challenge is nowadays the gold standard. Although reference values for prick test and sIgE have been proposed, which can foretell symptoms in groups of egg sensitive children, these values are not so accurate for a single diagnosis, since they mainly refer to children with atopic dermatitis, and to specific ranges of age. Children with atopic dermatitis can show allergy at the first egg ingestion, as for cow milk allergy, because the sensitization may happen in utero or through breast milk. The only available therapy in case of egg allergy is the complete removal of hen egg from the child's diet, yet considering cross-reaction with other birds' eggs, while cross- reaction with poultry and/or other birds' meat has been signalled only in 5% of cases. From this review it is clear how egg allergic children can be vaccinated against measles-mumps rubella.