Max's eyes

Max has dark circles under his eyes, they have always been there but lately people have been commenting on it so I decided to ask the GP about it. He said they are called 'allergy shiners' but he didn't want to send us for testing as there are no other obvious symptoms.
So I thought I would cut out dairy for a while and see if that made a difference. I made sure he had lots of non-dairy calcium. It's been over a week now and it's made not the slightest difference, so now I need to decide whether to try a different allergen or just let it be? It only bothers me because of the comments that others have made and I don't think it bothers him at all.