At my doctors appointment this week he observed what appears to be a large amount of histamine in my blood (I turned red very easily and it lasted awhile) and I also noticed I get red and hot randomly while indoors or out and it take awhile to cool down, I am a 33 year old female. He suggested Zyrtec at night but the next day after taking it I got red and itchy on my arm and other areas became uncomfortable like needing to continually crack my neck, back and mainly my two fingers on my right hand. The pharmacy suggested Benadryl but that did not help. Now it s been going on a few days, my itchy red fingers hat continually need to be cracked for relief were swollen and red this morning and very painful near the joint and continue to be painful although swelling went down a good bit throughout he day. Now I am becoming itchy in other areas like my left hand and my left ear is now bright red and very hot. I also suddenly have unexplained brushing across my lower back and right side. I am very worried, what could this be?