Maybe you are doing baby-led weaning, purees, or just going with the flow when feeding your baby. My son had some food reactions that I then had to investigate, so I have the following tips for you to consider, in case your kiddo might have an issue:
Introduce high-allergy foods such as dairy, peanuts, tree nuts, and eggs starting in the morning on a weekday in case you have to call the pediatrician due to a reaction.
Sometimes children can have a delayed reaction. Continue feeding one item during the week consistently because sometimes reactions crop up later after the child has more exposure and the allergen builds up in their system rather than during the first exposure.
If you mix the food with other foods, use a vegetable or fruit or something that is less likely to cause a reaction.
Try something that your baby has been eating for a while and hasn’t had a reaction to that food. For example, mix eggs with carrots (that sounds gross but whatever) instead of eggs with milk. When I was feeding my kids peanut butter, I had to mix it with something to get it to a consistency for them to eat it. I usually used bananas squished up in the peanut butter (is everything we feed to babies gross?). I used to put milk in the peanut butter but then it was hard to tease out what substance caused the reaction or whether both did. Potentially you can annotate which foods you are feeding when and how much so you can talk to the pediatrician about it as needed. I was the person that of course had no idea and didn’t remember anything so I will normalize that for you.
Some babies have sensitive skin, so their skin might have a reaction even though their actual body won’t (not anaphylaxis or a life-threatening reaction).
It’s a possibility. The reason I say to introduce new foods in the morning is so you have time to intervene appropriately no matter what is happening with your child’s reaction.
Most children have no problem eating new foods. I feel like as with everything in parenting, things happen when you least expect it and aren’t prepared for it. Hopefully, this will help you expect the unexpected and be a little more empowered.