A common way of diagnosing an allergy is by a skin prick test; this can be carried out at your local hospital. A tiny drop of a solution of the allergen is put on your child’s forearm and the skin is pricked. A positive reaction produces an itchy swollen lump with a white weal in the centre. The bigger the lump the more severe the allergy.

The most accurate way to diagnose a food allergy is an exclusion diet where suspect foods are cut out of the diet and reintroduced gradually to see if there’s a reaction. This type of diet should only be done under medical supervision and with the help of a state registered dietician.