Unbearably itchy upper body & scalp. no scabies, lice, dandruff, or allergies (tested). rashes on hands/inner elbows/chest. steroid cream not helping?

See Allergist: Given you unbearable itching symptoms and rash refractory to topical steroids I would suggest making an appointment to see an allergist for further workup/evaluation. Eczema, contact dermatitis, urticaria (hives), etc. are all skin condition that you could be suffering from. Getting workup up by a specialist might provide more answers/treatments.