My dad has prostate cancer and recently had radiation pellets implanted in the prostate.  He was doing fine for about 3 weeks and then contracted shingles.  He is really suffering with what the doctor called the "worst case of shingles he has ever seen".  Nerve pain and tingling is an ongoing thing now for over 5 weeks.  Just two days ago his left ankle started swelling up.  What could that be all about?
Please don't worry. I hope your father was offered acyclovir for shingles. Prednisolone is also prescribed in severe cases to reduce nerve pain. Other medications like amitriptyline give relief from neuropathic pain. Ankle swelling doesn't seem to have association with shingles and requires clinical examination to come to a conclusion