To update this. Mylan worked with my local pharmacy to send new patches of a different lot number, and to retrieve my current patches for QA testing. I am wearing the new patch now and have to see if the blistering was a one time problem or if they have a general problem with their skin adhesives.
I have to say that they were very responsive and proactive once I had established contact with them!
They old me that they did not receive any complaints in 2015 and 2016, which means, none of the people that were experiencing skin problems with the Mylan patches in 2015 reported any of this to either the company or the FDA.
No manufacturer can do quality improvements if they do not receive any information on quality problems.
It is very essential to report problems with medical devices and /or equipment to the manufacturer or the FDA!