I disagree with your doctor. Research shows that about 50% of recurrent outbreaks happen in the same location but that means 50% occur randomly in the boxer shorts area. The virus simply traveled on a different nerve of the sacral ganglia to get to the surface of the skin. It is appropriate to treat this recurrence, yes. The usual dose for recurrent treatment if 500 mg twice a day for three days. Usually the symptoms of a recurrences are far milder than the first outbreak.