Doug was a clinic patient in the Season 3 episode The Jerk. He was portrayed by actor David Bowe.
Doug got sunburn while working on his boat. However, he noticed that he had little white spots where sunburn should be. He was seen at the clinic by Gregory House and explained his concerns about the spots. He asked Doug to lie down on the examination table, got a syringe, and sprayed water over him. Doug was startled, but his son Mark thought it was funny. Dr. House then offered Mark the syringe and asked for the exact amount of change Mark had in his pockets. Mark gave him that exact amount. Dr. House then turned to Mark and asked if Doug liked to drink liquid from brown bottles and sleep on his boat. Mark nodded yes. Dr. House returned to Doug, took the change, and put each coin on Doug while he was lying down, perfectly matching the size of the white spots on his sunburn. However, he then noticed one of the quarters was Canadian and told Mark to give him his syringe back.