Hello,
Blister like sores causing burning sensation all over the body is commonly due to
herpes simplex virus. It can also cause
genital herpes. It is spread by direct contact.
You are suggested to get clinically examined by a
dermatologist, get HSV done as a swab test, blood test, or
lumbar puncture. Other tests may include PCR, STD tests, etc. If your tests are positive you will be treated with antivirals like acyclovir, famciclovir, etc.
Genital herpes may develop sores or blisters on the buttocks or around the rectum. Red wounds on or around the anus may cause pain, discomfort & burning.
Left untreated genital herpes may cause
swollen lymph nodes in the groin. Avoid sex till you are under treatment. It is contagious. Get treated at the earliest. You can apply Acyclovir topical cream on the affected parts for relieve.
Hope I have answered your question. Let me know if I can assist you further.
Regards,
Dr. Nupur K., General & Family Physician