I Have An Constant Itch For The Last 2,5 Months.

I have an constant itch for the last 2,5 months. No rash and it starts in the evening. I can't sleep and since last night my boyfriend is itching too. There are no bedbugs or any bugs cause then we'll see bites. Only rash we can see is the bumps that appear after scratching. I've been to 4 different doctors already.. no help