This is very interesting since I have experience similiar. When you fly, your body gets very dehydrated. I always purchase the largest water bottle offered at the gift shop right before getting on the plane and try to drink it ALL before I land. This way, I stay hydrated and I can be sure to flush myself out once I arrive (which can help with bloating). I also only bring certain snacks (a cut up fruit with some nuts, some turkey) to munch on if I feel like I need a little something. Hope this helps!
HI! I just started Gluten-Free for about a month (with some minor hiccups) and for a period of time my arms cleared up completely. Granted I was on vaca and I dont know if the sun/warm weather had something to do with it. However, these next couple weeks will tell. On a stickier note (concerning the Peanut Butter) I have removed PB from my diet since starting gluten free. I did this because I was experiencing discomfort after eating it. The peanut is a legume which has "similar traits to grains in their make-up; they contain phytates which inhibit nutrient absorption and cause inflammation" - source: http://www.livingpaleo.com/foods-to-avoid-on-the-paleo-diet/ Maybe you should try avoiding peanuts/PB for a couple of weeks to see if there is any difference