blister on roof of mouth

I have a blister on the roof of my mouth, as if I had eaten hot pizza, but I have not. The blister has gone but the skin remains sensoitive as if I had burned it.

[Evacrednow]

This occasionally happens to me.  Though a doctor has never told me this, I've always assumed it's like a cold sore blister on the roof of my mouth.  First there is a blister, then it is just tender skin for a few days.  If it's not a cold sore on the roof the mouth, I imagine it's a type of canker sore.  

[Dr Santos]

Hi,
How are you? Mouth sores can be due to cold sores, canker sores, or other irritation caused by trauma or injury like biting your lip, cheek or tongue and even ill fitting dentures. Cold sores begin as blisters and then crust over while canker sores appear as a single pale or yellow ulcer with a red outer ring. Cold sores are caused by herpes simplex virus and are very contagious. It is also associated with tenderness, tingling, or burning. If it persists, you may need to have this checked by your doctor or dentist for proepr management.Nerve causes should also be ruled out. Take care and best regards.