What Causes Itchy Rashes And Swelling All Over Body After Quitting Smoking?

A freind of mine is in a terrible state with a horrendous rash all over her body. It began last August with mild itching and has gradually increased getting worse and worse. She now has blisters up to 3/4 inch big. Her limbs swell to well over twice their size and the itching is unbearable. She has been prescribed every lotion and potion to no avail. She has has a biopsy tha\t evealed nothing. Her leg swelled like a balloon and they thought it was DVT but wasn't. She has been using steroid cream for 6 months which is not good in itself. She has seen dermatologists and has not been taken seriously which is a travesty. She cannot sleep through the itching and says it like being in a bath of nettles.
All this began about 2 weeks after she quit smoking. She is in her mid 50s and smoked for most of her adult life.