Social stress gave me a case of the shingles once in my twenties. It didn't make much sense to me at the time, but for some reason being stressed out about buying a bunch of Christmas gifts late in the season caused it to happen!
I had a coworker who developed shingles as we were nearing the deadline on a project that had all sorts of problems in layers of the stack we didn't control, and my sister developed shingles after being laid off. The first thing I associate with that disease is stress.