In House, MD season 7, episode 7, “A Pox on Our House,” Dr. Gregory House (Hugh Laurie) risked his life breaking a smallpox quarantine - because he was positive it wasn’t smallpox they were dealing with. The setup to the episode makes it seem like a straightforward case of the disease. While diving in the wreckage of a ship, the patient breaks a glass jar full of scabs, seemingly exposing her to a preserved sample of smallpox.
When the case reaches the hospital, the CDC is quick to lock down the hospital and put the girl and her family into quarantine. Her stepfather quickly develops the disease as well, and House ends up locked in quarantine, dressed in a protective hazmat suit, after trying to treat the father’s other symptoms. As things worsen, it looks like House is running out of opportunities to get out of this alive.
Everyone on the team except for Martha Masters (Amber Tamblyn) is convinced it’s smallpox, but she can’t get close enough to the patients to be able to prove it. Her only recourse is to consult a translation of other evidence found in the wreckage, and an anecdote about the ship's captain's cat, who lost all its fur before it died, provides Masters with the clue that breaks the case.
She convinces House to investigate the stepfather, who died of the disease quickly, in order to check for eschars on his body. This would show that he and his daughter didn’t have smallpox, but Rickettsialpox (R-pox), a nonfatal disease, which causes cats to lose their fur and is transmittable to humans, with many similar symptoms to smallpox. However, Dr. Dave Broda (Dylan Baker) of the CDC, who’s in charge of the quarantine, refuses to treat it as anything but smallpox, and fears that any quarantine break would let smallpox loose. Smallpox test results are on their way back, but not before House’s oxygen tank runs out. They could give him another tank to swap out, but that risks exposing him to smallpox.
Stuck in a hazmat suit in the quarantine room, House eventually removes his gloves to check for eschars, breaking quarantine. If House and Masters are wrong about their R-pox theory, House's quarantine break would mean certain death from smallpox. House searches the body, and he finds the eschars as the CDC doctors are coming in to bleach the stepfather’s body, which would kill any smallpox presence but also eliminate the evidence. With the discovery that it’s R-pox, a simple antibiotic treatment treats House and the original patient.
As happened many times throughout the House, MD, House ended up being right despite highly questionable actions. He broke the quarantine to treat the patient in this episode and later to show the actual cause of death. As is his usual way, he was incredibly reckless, even if he was ultimately right about yet another diagnosis.