If you kill Sjoorm at the same time as the "bubbles from sky" -- whatever it's name is -- aoe goes off and get hit by them, the Dropsy debuff will not clear properly and will persist through the whole dungeon. I believe it's because of a very small window between the skill going off and taking the damage and the boss dies during that time.
http://i.imgur.com/ZAc3xIg.jpg
At least it disappeared when I left the dungeon.