Question about very rare skin disease?
If anyone is in the dermatology field, I am looking for information about the disease called bullous pemphigoid. Last week, my grandfather had joint replacement surgery on his knee. One day after the operation he began developing large, draining blisters on his leg around the incision site. The blisters have multiplied and look bad, but there is no skin infection. The doctors are now questioning whether it could be pemphigoid. Is it usual for that disease to occur in only one spot on the body (left shin only)? I know it is an autoimmune disease, but is it possible the surgery could have somehow triggered the eruption? He is doing ok on antibiotics, but no one seems to have an answer for what caused the bullae.

they might have an answer for you there..
I came here hoping to find an answer to my problem when I noticed your question. Unfortunately, I don’t know what is causing your grandfather’s blisters. This is weird! I had joint replacement surgery on my knee 6 months ago. Three months after the surgery I developed a small patch of draining blisters on my leg around the incision site. After a few weeks the blisters started drying out.
I went to the knee surgeon and my family doctor and a clinic and I was told it is eczema. I was given a cortisone cream but it has not helped. I still have the patch of blisters on my knee and every once in a while they flare up.
I don’t know if this is in any way related but, about a month ago, I woke up in the middle of the night with large red welts all around my neck. They burned and were very itchy and the area around my knee, which had calmed down a bit, became red and inflammed again. I saw doctors and was again told it is eczema.
This morning I again woke up with more welts around my neck and smaller welts (like a fingerprint) on my face. I feel like I am on fire. Tomorrow I will contact my doctor and mention this bullous pempigoid to him.
Was your grandfather given tetracycline, or steroids (prednisone)?
This is an autoimmune disease which could have been triggered my his surgery. Try. I am not a doctor, but had thought at one point that I had this. Only a biopsy will tell. Several of my suspected Pamphagus spots went away. what remained ended up being basil cell carcinoma. Good luck!