Fear Of Butter

Well, my little brother has a fear of butter. He cant eat anything with butter on it. He cant get stuff out the fridge becasue theres butter near it or on top of it (even if its in a tub). If he sees butter he will instantly be put of eating. The word ''Butter'' Puts him of eating.The smell puts him of eating. H e cant touch the tub either. What is the reason for it. Do many people have it. Is there a way to get rid of it.