I don't know if I actually have a mast cell disorder yet, but have had a normal tryptase on 2 occasions, a normal n- methylhistamine 24 hr. Urine, but elevated 24 hour urine prostaglandin d2 and f2 . I also did a 24 hour 5 HIAA which was normal. I have muscle pain, flushing, itching, pins and needle sensations in skin with a bitter metallic taste in mouth. I am miserable and am trying to figure thing out. Advice from you all is appreciated!