If there's no history of food allergies, than the recommendation has shifted to introducing all foods, even those considered "high allergens" as soon as the child is ready for solids ( around 6 months). I was totally shocked, and did some research and reading,They are now saying that one of the key factors in severe allergic reactions is withholding allergenic foods to which children have a mild reaction early on - by withholding the foods at an early age, the body reacts more strongly when exposed at a later age.
I recently came across an article ( found here
http://www.newyorker.com/reporting/2011/02/07/110207fa_fact_groopmanP ). I did ask around, and many of my friends pediatricians (as well as a friend who has a daughter who sees an allergist) also recommend starting earlier. With DS1 I introduced it around 9 months, DS2 has some other allergies, so we are waiting until he's a little over 1.
Since you think your LO might have a food allergy, I'd ask your pediatrician (or allergist) and see what they say. My friend who's child has other allergies began by rubbing peanut butter on the outside of her LO's cheek, if no reaction, she then placed a little peanut butter on her lip, and again waited for a reaction. Then she allowed her a small taste. If you're concerned you could always take it very slow with the introduction.
