What dosage of antihistamine should i take to resolve a mild food allergy reaction?

Any recommended: Dosage of any OTC antihistamine, either first or second generation, will be effective, more important though is avoidance of re-exposure to the offending food till problem is sorted out. Keep antihistamine handy for accidental exposure, if severe reaction, keep epipen (epinephrine) handy too, see your doctor/allergist if the problem is bothersome, best wishes