Thanks for writing in.
The condition you are suffering can be dermatitis herpetiformis
It cause blisters with itching over lower part of the body.
You can take tab zyrtec for itching and apply Soframycin
cream over affected area.
Consider a visit to dermatologist
for prescription drugs.
may be needed for diagnosis.
Discuss the option of Dapsone with your doctor.It is a wonderful drug and will help a lot in long term remission.
Hope this helps.