It really helps to hear all this, thank you.  My daughter currently has no
dairy whatsoever in her diet, we do not take chances very often and nearly
everything she eats is homemade (so I am sure of its dairy-free status).
Like some of the previous posters, I do not notice the dark circles during
late spring, summer or early fall for past two years, only mid-October to
mid-April.  Although I definitely will ask her pediatrician about the
possibility of other food allergies being at play here.  I really like her
pediatrician a lot and value his input and I know this is stupid to say
but I worry that if I make too big a deal about the dark circles that he
will end up putting her on lots of medications and in principle, I don't
like that idea.  But of course I want what is best for her and what will
make her feel best.  She has her 5-year checkup coming up soon and I am
making my list of Q's to ask, and this is definitely on the list!