I am working with a mom who has some food allergies herself. Her 3 month old seems to be healthy and growing, but there is just something nagging at me. So far, all I know is that she spits up long after a feeding, has eczema or dry rough skin (mom claims it's just dry skin) all over her body, and cries a bit before pooping. Is there enough for you to suspect that there is something more than just regular newborn stuff going on?
It def. could be an allergy. She could try eliminating all dairy/all hidden dairy from her diet for 2 weeks and see if she can tell a difference.
If there's no difference, then try eliminating egg/products with cooked egg in them for 2 weeks.
She could add them both back in and try eliminating common allergens, like peanuts/tree nuts or eliminate any foods bad for reflux (fried foods, tomatoes, oranges etc).
My 18mth old started out very fussy, reflux-y and now has eczema on his head. He has confirmed food allergies, including corn. I hope that helps <3