Hello."Shingles" are vesicles over the course of the nerve
."Shingle" is a sign of herpes zoster
virus.If shingle has not appeared, probably his father's pain is not caused by herpes zoster virus and antivirus drug (famciclovir
or other)is not suitable.There are other differents causes for the pain of your father.
Go to your Doctor to Consider other causes of the pain.
I wish you good health.