Honestly peeples if it were me I would get another doctor. I had this discussion with Daughter of Maat over seaweed. Some conventional doctors are going to tell you it will do no good, a holistic doctor that deals with herbal cures will tell you to go ahead and consume seaweed. "Ask your doctor" needs to be taken with a grain of salt.
The same thing with honey. I know locally grown and harvested honey is indicated in allergy control in dogs, too, but if you ask a lot of conventional veterinarians, who give steroid shots and sell antihistamines during the inhalant allergy season, they will tell you it is no good. If you ask a holistic veterinarian, he will tell you it is a good idea. Who is correct? Neither has a degree "better" than the other.
I am not sure about the development of the immune system of children, but 5 seems very late.
I really think you should consult a holistic physician on this issue.