Analysis of the positivity rate in IgE positive patients to food allergens in Verona Hospital laboratory during 2003.

Background: It has been known for some time now that reactions to allergens, not only those inhaled but also those in food, varies with age in atopical patients.
Objective: To evaluate the specific IgE positivity percentage in order to improve laboratory diagnosis in subjects with suspected food allergy.
Methods: The positivity percentages of specific IgE were analysed (UniCAP100-Pharmacia) taking into consideration the two age brackets of below and above 12 years. The below 12 years age bracket was then further divided into pre-school age (3-5 years) and school age (6-12 years).
Results: By measuring the simple positivity percentage for specific IgE to food allergens, there is a clear decrease as the child matures in reactions to milk and eggs and an increase towards food IgEs that cross-react with grass and tree pollens or other inhaled allergens like moulds and mites.
Conclusion: It will be necessary in the future to have the diagnostic means to identify this cross-reaction problem by using recombinant allergens that can demonstrate the combined reaction between inhaled and food allergens.