Most of the patients that I see with food allergy are less than 10 and under 5. And the same really with hay fever - with respiratory allergy. It tends to be younger children who develop hay fever. As they get older often what you find is that the symptoms of the hay fever generally subside a bit and they get more in the way of asthma symptoms.

Some allergies can develop at any age so for example things like nickel sensitivity may develop at any age. Sensitivity to penicillin and certain other drugs you can develop as you get older. But by and large if you are free from allergies, hay fever, asthma and eczema by the age of thirty you're unlikely to run into trouble as you get older. One of the benefits of getting older I think.