Allergy weaning- advice needed!

Hello,

I cut out dairy, soy, eggs and nuts from my diet after my LO seemed to get rashy after I ate any of these. She is 4.5 months and I want to start weaning as per a dietician I spoke to who said the earlier you introduce allergens, the less likely to develop allergies later. She said to introduce them in tiny bits at first and keep having them to develop a tolerance. Should I keep giving it even if it causes a rash to build this tolerance? Does anyone have any experience or advice as I don’t know the best way to approach it. Thank you!