Itchy rash all over body. Gets worse at night

Please help! My brother (54yrs) has had a rash all over his body for over a year. We've been to 10 doctors, he's even had an MRI/catscan of his liver to make sure he doesn't have sorosis of the liver.  The test resulted in a healthy liver.  We've tried over the counter and prescriptions and nothing works.  They look like tiny little red bumps scattered over his arms, legs, torso and back.  Please help.  Does anyone have these symptoms? The doctors can't help and he is in agony. He is scratching so hard he bleeds.  Someone please help!