Teleportitis (5e Disease)
From D&D Wiki
This disease can be contracted on occasion when travelling through the Ethereal plane with an open wound. It is contracted if you fail a Constitution roll with a DC of 8. Every day, you may make a constitution roll with a DC of 12 and after 3 successes, the disease fades.
While afflicted with the disease, your nose itches and every time you sneeze, you teleport to a random location within 30 feet that you can see, as if by a Misty Step spell. The disease's strength is increased with adrenaline, and you may sneeze at the start of your turn in combat. Roll a d6, and the character teleports on a 6.