Hi,Customer, these blisters around your penis ring could be caused by : an allergic or irritative process .
Sulfameth can produce allergic reactions,however ,in most cases when the skin allergy is produced by antibiotics ,the irritation will spread over more extensive areas and not exclusively in your penis .
However ,It is extremely important that You consult a doctor to rule out other possibilities like the presence of a Sexual Transmission Disease ( STD) like Genital Herpes or other type of skin Bacterial or Fungal infection .
You should consult a doctor to evaluate you as soon as possible so these lesions do not get worse .
The doctor should perform some STD blood tests to rule out this possibility .
If this is only an allergic reaction , the doctor will probably prescribe you a low dose Hydrocortisone cream for 5-7 days to relieve your symptoms .
If you like the answer,please click accept . A bonus will always be sincerely ***** *****