Suggest Remedy For Skin Problem At Night

I am 25 years old, 110 pounds and 5 feet 2 inches tall. I have chronic insomnia and one of the primary reasons I stay awake (other than racing thoughts) is because my skin becomes sensitive and itches. My skin does not itch during the day, I use the same detergent for my sheets as I do my clothes, I do not use an antihistamine during the day, and I do not have any abnormal bumps, rashes or lesions. Any ideas as to what is causing this and what I can do to alleviate it?