Those of a delicate disposition, look away now

Well that'll serve me right for being so optimistic yesterday. Last night I couldn't get to sleep for ages because the blasted itching was back, driving me demented. It was like having little devils in nettle boots scampering from one site to another, occasionally tormenting me with a minute or two of comfort before starting up all over again. Nothing I did seemed to ease it and I'm still uncomfortable today, I scratched some areas so much. I wish I knew what sets it off.