Shingle Nerve Pain

My Great Aunt is 94 and has been suffering with residual nerve pain after a bout of shingles 15 months ago. It is mainly on the left hand side of her abdomen into groin and extends sometimes down her left leg. Leg often numb - feels like it would give way if stepped onto suddenly. She can't say what makes it worse - there's no pattern. She has lost her appetite but despite losing 20lbs (now 6.5 stone) has maintained the same weight now for six months. She is bright, mobile and otherwise healthy, taking no medication. She was a sickly child and had many colds, ear infections and sinisitus (mostly on left)- this all stopped when she retired from a busy clerical job. She lost both her parents when a small child, brought up by her aunt. Two years ago she lost feeling in left forefinger after carrying a heavy shopping bag. She tried taking Capsicum 200c but stopped when the pain worsened. Can you recommend a course of action for her please.