Wow, Flycaster. Just wow. And so sorry that happened to you, by the way. I think it's good that you posted it, though. Someone might need to know this. It's not the kind of information that you come across every day.
I had the same symptom as your husband.
In my case, I went through a very long, unsuccessful stenting procedure several years ago, the blockage couldn't be reached. I had eight previous stents so have had a lot of angiograms. About a month or six weeks after the procedure, my back itched a great deal over a large area of my back, but particularly in one specific area. One evening it was particularly bad and my wife lifted my shirt to put on lotion, and stated in disbelief, "you have a 2 x 4" square burned on your back!"
It was a radiation burn from the stenting procedure. I knew in advance that was a risk factor as the procedure would be difficult, and knew that bypass was the next step.
I'm fine today, but still have the scar. Typically, the burned area won't show up for weeks, maybe months after the procedure.
I'd urge you to contact your Cardiologist, who I'm sure will check your husband out and probably refer him to a skin doctor. That is what happened in my case, and some topical medication was prescribed that gave me a lot of relief.
Since that incident I've had a bypass that failed and new advances in stenting procedures allowed me to have another try at a stent in the native artery which was successful. Of course I had more radiation from the procedure, but extreme care was used to limit the radiation time, and I haven't had any radiation burn symptoms.
I hesitated to post this as I worry I'll scare people away from the procedure, but my history involves hours and hours in the cath lab, and I'm still standing.
If you have more questions, please feel free to send me a private post.
Like ed34, I would review the medications your husband is taking. Your husband should talk to his doctor and/or pharmacist about this. Oftentimes, pharmacists will have even better info about the side effects of drugs than doctors do.
An allergy to something in the environment or to one or more foods is also a possibility. I have an itchy spot on my back that my allergist has diagnosed as eczema, and I do not have any stents in my heart and do not take Plavix. I have allergies to dust, dander, and pollen.
Good luck on finding out what is the problem. Personally, I think an allergy to the stents is extremely, extremely unlikely. There is a much greater probability that the itching is caused by something else besides the stents, which is good, because pretty much anything other than the stents will be easier to eliminate. Try to think of anything that changed -- starting Plavix or anything else -- in the few days before the itching started.
Is he taking clopidogrel (Plavix) ?