I'm not sure. One possibility is herpes, essentially a "cold sore" in a less-common place. This is just an annoyance, but you should be examined for diagnosis and treatment. A doctor should see you the next time the blisters are fresh. Culture will tell the tale. Then you can decide what's best to use.
Take care.
Dr. Rockoff
I have this too! It usually occurs only in the right ear. It is thought o be related to my metal allergy problem but not confirmed. I have a 12 lb limb salvage porosthesis that started all my problems.
Bonnie