Question: I keep getting these rashes on my body in different places. always from shoulder downward. raised a little and looks like mosquito bites but in larger areas. if I feel an itch and scratch an area it gets the rash look in that spot and is in the exact spots that I scratched.it goes away usually in less then an hour and is worse at night. I had it months ago and just came back again. it is very itchy at night. what can that be ? how can I determine what it is?

there is no fever or burning. just starts to itch with nothing noticeable on skin and when I scratch it gets red and raised up within about 5 minutes. it resembles mosquito bite the way it looks but its a large area. not anything to do with bug bites. its less during the day and 90% at night time which is much much worse then. when I scratch you see raised lines where the fingers scratch the skin in 5 minutes. if I just pick a spot on my harm and scratch it , it will get red and raised up in 5 minutes without there being any itch. sometimes if I bump into something and scratch the skin the same thing happens in that spot. then it just goes away after an hour or so. does not increase in the AM. it happens very little in day time. its not everyday that it happens. im not sure why it just stopped a few months back. I live in long island new York. I can send pictures tomorrow.