I am 26 and have been allergic to all nuts (including imitation almond extract) and have unfortunately dealt with this my whole life. Although some airlines do have policies in place, there frequently is poor communication between reservations/gate agents, and catering. I have found that taking 50mg of Benadryl (see my heading, ASK your doctor) can prevent the onset of anaphylaxis due to peanut dust. By all means try to get the airline to enforce whatever their policy is, but I have found that this is the next best form of life insurance besides an Epi-Pen (I always have two in the cabin with me).
I cannot stress enough that you should speak with your internist/allergist/pediatrician. I have noticed that most of the messages on this site are from parents, and some of the children are very young. At young ages, it is very difficult to determine the severity of what your child is enduring.
At this point in my life, I have seen my share of ERs around the country and know my body very well. I know if I'm reacting within two seconds, and after about 30 can determine if I need to: (1) take Benadryl, (2) Benadryl + Albuterol inhaler, (3) Epi-Pen, or (4) Epi-Pen + get to an ER.