House S7EP10 “Carrot or Stick”
New semester, new episode of “House,” what more could you ask for? This is one of the few shows that I try to catch when new episodes show (Spartacus: Blood and Sand was the other one; don’t judge me, we all need some downtime once in a while!) Since the show frequently deals with issues of infectious disease, and therefore microbiology, I decided that it might be helpful to examine the diagnostic procedures used on the show, and evaluate the feasibility of the presented scenarios. From the Fox.com website synopsis of this week’s episode:
A teenage military trainee at a juvenile offender training camp suffers peculiar symptoms after enduring an intense training course, and mysteriously, his drill sergeant is soon admitted for similar symptoms. Unable to track down the cause of the shared illness, the team searches for clues in the trainee’s family medical history, and Masters and House reveal a unique bond between the sergeant and trainee.
The synopsis also covers the continuing saga of House and Cuddy, along with some some bad Facebook status updates for Chase. Why don’t we focus on the Microbiology? Before watching the show, here’s my initial impressions: two individuals with similar signs and symptoms. It can be an infectious disease, either with direct/indirect transmission from one to the other (the most common mechanism of infectious disease transmission,) or via exposure of both individuals to a common environmental reservoir for the disease. Essentially all fungal diseases are transmitted to humans via exposure to something in the environment, and are extremely rarely transmissible from an affected individual to a healthy individual. One other possibility that I will put out there, prior to watching the show; maybe we have a genetic predisposition to the disease, which has gotten triggered at the same time, and no infectious agent is involved. Let’s see how I did!
8:01 PM: Boot Camp. The mean Marine Sergeant collapses while yelling at grunts to climb the wall.
8:08 PM: Chase regrets the choice of “password” as his Facebook password.
8:09PM: Sergeant exhibits PTSD flashback, in addition to nondescript abdominal pains.
8:12 PM: Time for the differential; best choice at present is antihistamine poisoning by one of the other “guests” at juvie camp, however Masters and Foreman suspect motive, but find no evidence of poison.
8:21 PM: Tachycardia symptoms are not resolving with fluid replacement and adenosine therapy. House suggests looking at fluids coming out the other end. Time for an MRI, which isn’t showing anything.
8:29 PM: Uh oh! The juvie just showed up in the ER, with the same symptoms!!! Time to look for a common cause to explain what’s going on. Shampoo? Toothpaste? Deodorant? Sexual history? Nothing is panning out. Best guess right now is Lyme Disease, so start the patients on doxycycline.
8:37 PM: Drill sergeant starts having extreme pains in his legs, so Foreman prescribes diazapam (Valium!) stop the spasms. Cramps due to low sodium, due to kidney dysfunction.
8:43 PM: Taub suggests botulinum toxicity. C. botulinum lives in soil; the drill sergeant got it from cuts in his feet, and the kid got it from the cut on his head. Time for antitoxin.
8:46 PM: House figures out that the drill sergeant is the kid’s deadbeat dad. Am I good or what? Best guess now is heavy metal poisoning from some abandoned batteries triggering both of them.
8:53 PM: House gets the epiphany. Lidocane injection triggered porphyria when the kid got his forehead stitched up. They both need a liver transplant, but fortunately they only need one between the two of them!
So what is porphyria all about? It is a genetic deficiency in one of the enzymes in the biochemical pathway for heme biosynthesis. The result is that there is a deficiency of heme and accumulations of porphyrins, the precursor of heme. The heme deficiency is surprisingly not the problem here, although you would expect it to be. Porphyrin accumulation can lead to liver damage, prompting the symptoms observed by both patients. From Wikipedia, these include “seizures, psychosis, extreme back and abdominal pain and an acute polyneuropathy.” Once identified, supportive therapy to manage the symptoms is generally successful. Many times, as we saw here, there are environmental or chemical triggers for the symptoms, and they can also frequently be triggered by infectious agents.
I like to wrap this up with examining the feasibility of the scenario. Genetic diseases such as this are probably more frequent that you might realize, and the incidence in the United States of the various porphyria-associated diseases is approximately 1 in 25,000. House and his team likely would have hit the diagnosis very early on in the episode if the kid had showed up sick at the start of the episode with his dad; a genetic link like this is just too big of a red flag to ignore. I, therefore, had a big advantage to the TV doctors by reading the summary on the network website. Go me!