1.2 y.o with atopic dermatitis

My son 1.2 years old suffers from atopic dermatitis. It started in March after enterovirus and very high fever. Since then we have better and worse days, mainly nights he does not sleep and suffer. We believe pruritus is the source for difficult nights. During the day, it seems less destructive, but he moves from one thing to the other, rarely concentrate upon one thing. We recently have tested for allergy skin test was negative and RAST test negative too. We feel it is related to stress and heat. When he cannot return to sleeping at night 2am normally at worst 4am better nights, we put a mattress on the floor where A/C flow reaches. That help to clam him down and returning to sleeping.
Conventional medicine we tried all sorts of creams and lotions, antihistamines and steroids. All gave minimal improvement.
Alternative medicine, we had series of acupuncture but still had exacerbations. Homeopathy, we tried sulphur 6c, again no improvement.
Suggestions appreciated.