After a bout of the “flu”, a 30-year-old man notices several painful 0.3-cm, clear vesicles on his upper lip. The vesicles rupture, leaving shallow, ulcers that heal over the course of 4 weeks without scarring.

Several months later, after a skiing trip, similar vesicles develop, with the same pattern of healing. *This case is from Docplexus editorial team for educative purpose only Source: Internal Medicine