Food allergy

Hi I think my baby had a mild food reaction to red pepper. I gave it him 2 days in a row and whilst he was fine he got a red rash on his face. The first day it was quite hot out so I didn’t think much of it and thought it may be a heat rash however the second day after lunch he got this again. My question is what do I do now? Do I avoid giving him red peppers or as it was mild do I wait and try it again at a later date? Thanks