The number of children with deadly peanut allergies and allergies to milk, eggs, wheat, and other allergens has been rising. Allergies are now affecting 1 in 13 children.
It has been recommended to avoid introducing the common food allergens to children while they're learning to eat and before a year old because introducing them too early can lead to them developing allergies. There has also been a theory tossed out that introducing them early can help them build up the immunity to avoid an allergy.
In previous generations, they didn't always wait to start giving babies foods later. They didn't know as much and they weren't as paranoid as newer generations, but as time has gone, they have retracted the strict guidelines and we are now left with very little to go on.
There are eight major allergenic foods that are of higher likelihood to cause allergic reactions: peanuts, tree nuts, milk, wheat, eggs, fish and shellfish. Those can cause anything from mild (eczema or minor asthma) to life-threatening (severe asthma or anaphylactic shock).
From four months on, baby can be introduced to foods. It is recommended to start one ingredient at a time and it is important not to introduce new foods for a few days, to make sure that no allergic reactions start.
"Egg, dairy, peanut, tree nuts, fish and shellfish can be gradually introduced during the same four to six month window after less allergenic foods have been tolerated. In fact, delaying the introduction of these foods may increase your baby’s risk of developing allergies." (from the AAAAI's website, you can find the quote here)
But what are the symptoms to watch out for?
The symptoms to watch for are rash, itching, swelling around the face, diarrhea, eczema rash, trouble breathing, distension in the stomach. If any symptoms like trouble breathing come on after introducing a food take the baby to the doctor immediately. If minor skin rashes come up, make an appointment to see an allergist.
The best way to go about introducing foods is to keep a food journal. Mark the date of introduction and any reaction or lack of reaction.
It wasn't seen as dangerous to introduce babies to allergens early on decades ago, then they started to see a rise in allergies and identified eight that became more severe but now it seems they are going back to finding that earlier introduction can help build the protection babies need. When you introduce the eight big allergens is solely up to you (and your baby's pediatrician's guidance will help) but it seems there is no actual agreement one way or the other.
Of course, consult your doctor first to determine the best plan for you and your baby.