I had a sandpaper like rash on my upper arms my entire life which completely cleared after a few MONTHS being gluten free. I had had blood testing for celiac which was negative but despite that I tried and had a positive result to a gluten free diet trial. For sinus issues my son and I both have had excellent results with Nasalcrom. I double dose myself and sniff hard to get some to go down my throat every morning and have stopped getting bronchitis/pneumonia. Of course, check with your doctor. Be careful about histamine in foods… leftover meats are really high in histamine. I got sicker on GAPS because of the added histamine in fermented veggies and long simmering meat and broths. I can get abdominal pain and bloating when I eat foods with too much histamine. It is a barrel-effect so you can get away with some foods sometimes and not others. I highly recommend Maria Emmerich’s blog and books for gluten-free low carb HEALTHY food recipes which my kids love to eat!