P.F. Chang's has a fairly extensive gluten free menu and if you choose items that are vegetarian as well you can pretty much avoid all the major food allergens. They do warn, as is the case in almost all restaurants, their food is all prepared in a common kitchen where other food allergens exist. If you are highly sensitive, consider yourself warned. I ate at the P.F. Chang's in Austin, TX and I have to say, I was impressed with both how accommodating they were and how knowledgeable our waiter was! He was able to offer me suggestions and personal opinions about the dishes. I had the GF Singapore Street Noodles, which consists of shrimp, chicken, vegetables and rice noodles stir-fried in a gluten free sauce. They were delicious and filling. I even splurged and had their GF Triple Chocolate Mousse Mini, which has three layers of chocolate ganache, milk chocolate mousse and flourless chocolate cake. It wasn't completely allergy free for me, but it didn't upset my stomach too much... and it was heavenly!
P.F. Chang's is a great option for those of us with special dietary needs. They are knowledgeable. If you have someone in your party with other special dietary concerns ask to speak with a manager or the chef, and they will try to accommodate them as best they can.