Sorry for the delay in getting back to you.
The blisters on the image look like a flare-up of a herpes infection.
Herpes infection, as you probably already know, is a viral
infection, which, once an infection occurs, stays in the body for a lifetime. It can cause occasional flare-ups from time to time.
The blisters that you have are very typical of herpes blisters. Herpes blisters occur in clusters and are usually very sensitive or painful to touch.
Herpes infection can occur by oral as well as by vaginal and anal sex.
A blood test should tell you if you have herpes. And your doctor should be able to prescribe an ointment like Zovirax to apply on he blisters.
I hope this helps.
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