 [ Symptoms ] my 3 yr old has thrown up twice after eating peanut butter and a peanut cliff bar but has eaten peanut butter before i am wondering if this could be an onset of an allergy she also has some itchy patches on her chin below her lip should i see a doctor [ Disease ] certainly a peanut sensitivity allergy food intolerance  may exist il would think it wise to have an allergist test your child for a peanut allergy just to be safe in the meantime avoidance of peanut products would be prudent