The rash of herpes zoster usually shows up along the path of the nerve that is involved. In this picture, the path of the branches of part of the trigeminal nerve gives the rash a sharp boundary between where the vesicles (bumps) appear and where they do not. The appearance of a vesicle on the tip of the nose indicates that one of the small nerves that connects to the part of the eye may also be affected and indicates an increased risk of severe ocular involvement.