What Causes Itchy Skin After Changing From Lortab To Tylenol?

My skin is so itchy... it s not fleas! Nothing on dog or cat. I changed med s from loratab to tylenol 4 .? Last year i was diagnosed with anemia and ulcer. Both gone now. Also, my hands/wrist go numb in bed but i even feel it a bit during the day. It wakes me up about 3 times a night where i can t feel anything. Could this be from cell phone? Im also a violinist/teacher and play all day ( 30 years) but this is new, the numbing. I take blood pressure meds, but maybe my blodd pressure is low /lack of blood flow? very concerned about my hands! thanks for your time. Kathy mka