My Wife Has Had A Dry Cough For 8 Months

My wife has had a dry cough for 8 months after a stent was placed. it started when she was still in the hospital. we have seen many different doctors about this problem. we have changed all her meds and it seems to be getting worse. she can't sleep at night because of it and is so worn out she thinks she is going to die. her body hurts and her skin hurts when you tough it. she has also developed a rash.. it seems like no one will take it seriously. could she be allergic to the stent? give us a suggestion where to go from here.