Weird one. I have woken up with a blister on my elbow. About the size of a 10p. It’s sore. I slept in a long sleeved top.
this isn’t the first time. It happens approximately once a year, usually on my elbow, once on my bum. Happened in different countries, so not tied to my home. Always sore, always leave a scar.
What on earth is causing them?