These ‘Zebra’ Cases Were Cracked by People Other Than Doctors

Every medical school student has heard — likely dozens of times — that when it comes to differential diagnoses in clinical practice, “when you hear hoofbeats, don’t expect to see a zebra.”

Most of the time, hoofbeats come from horses; but not always. Many clinicians have their “zebra stories,” those instances where they went against those odds, trusted their hunch, and correctly landed on an uncommon or unexpected diagnosis.

A recent thread on Meddit, or medical Reddit, takes the zebra story even farther, calling for the “most obscure but correct diagnosis you’ve seen suggested by a non-physician.”

Dozens of people have since shared their favorite zebra stories initially suspected by a patient, lab technician, or first responder, and the results were — as one commenter put it — “like watching House in text.”

‘Baby’ EMT’s Bad Feeling

One popular response came from a commenter with the username AnonymousAlcoholic2:

“Guy called 911 for weakness and abdominal pain. Initial assessment didn’t trip my sleepy alarm bells at 2 a.m. because he said it felt like his hernia was flaring up. Before I asked him to stand and move to the stretcher my EMT [emergency medical technician] said he had a bad feeling. Smart kid but a baby EMT with less than a year but he had the balls to speak up when he had the spidey sense. Said he was worried it might be a AAA [abdominal aortic aneurysm], but he couldn’t figure out why. That woke me up because I had watched a guy around the same age die in front of me not long before this from a burst AAA. Sure enough his legs looked pale compared to the rest of his body and I about died myself when I felt the pulsating mass. We carried him out and handled him like a porcelain doll the whole time. Repair was successful and he lived.”

Thick Blooded

Another story came from a lab tech by the username of edwa6040:

“I am a lab tech. I called a multiple myeloma just by looking at the centrifuged blood. It took a week to get anybody to listen to me and order the ELP [electrolyte panel] because the serum protein was always reported as ‘normal.’ Because there was so much protein in the blood that it would spin down to a tiny fraction of liquid and a huge layer of basically slime that we couldn’t use for any chemistry analysis. It was so difficult even drawing her blood — we could get like 2 or 3 CCs and it would just stop flowing. Her blood was literally just that thick. I talked to every one of the patient’s doctors, finally she was handed off to coincidentally our chief of staff who listened to me and told me to go ahead with the ELP, he was actually a little surprised nobody else had pursued that yet. Sure enough huge M spike.”

A Husband’s Wild Guess

Another commenter — with the username Mobile-Entertainer60 — shared a once-in-career case:

“Had a seemingly healthy patient with obscure recurrent hemoptysis, CT w/IV contrast was unremarkable. Had been given antibiotics for ‘bronchitis’ multiple times without long-term relief. Patient’s husband swore up, down, and sideways, ‘It’s her heart that’s doing it doc, I know it, I can always hear her heart.’ Heart murmur on exam, didn’t think much of it, planned for a bronchoscopy for the hemoptysis. Found bronchial varices due to severe mitral stenosis from probable prior rheumatic fever. Valve replacement fixed her hemoptysis.”

“A one-in-a-career case, for sure. Immigrant from a developing country so the risk for rheumatic heart disease was definitely higher than a U.S.-born person, but even if I knew they had mitral stenosis, I don’t think I would have gotten to bronchial varices as a cause of hemoptysis pre-bronchoscopy. Husband had a wild guess her heart murmur and hemoptysis were related and was proven right.”

Smoking White Flower

One of the most-liked stories on the thread came from a commenter with the username Notgonnadoxme:

“My favorite example of the EMS [emergency medical services] zebra was from a 30/yom [30-year-old male] with palpitations. Somewhat elevated BP [blood pressure], HR [heart rate], RR [respiratory rate], etc., flushed but not diaphoretic, highly anxious. My partner immediately triggered onto possible substance use and asked about stimulants but patient denied. Then said, ‘Oh I did smoke a plant with a white flower on it, but I can’t remember the name.'”

“Me: ‘Was it Jimsonweed?'”

“Patient: ‘Yeah that’s it!'”

“Cue an incredulous look from my partner and disbelief for the rest of the night. I recognized the prodrome because I took a college course about plants historically used in religious ceremonies and for some reason it stuck in my brain. Ended up doing anxiolytic doses of midazolam for symptom management/patient comfort and transported to the ED [emergency department] without issue.”

The commenter later added: “It just occurred to me that this is an example of both non-medical education being useful and anthropology providing actionable information that can impact patient care today. Kinda neat.”

Raccoon Roundworm

Another popular response came from a commenter named thebighead:

“Had a case of Baylisascaris (raccoon roundworm) meningoencephalitis back in med school. Guy was a contractor who regularly ate lunch w/o [without] washing his hands after doing work under the house, where a bunch of raccoons had been nesting. He was also an avid hunter, and had killed a bear and eaten its meat a few months prior to symptom onset. When the case was being presented at morning report, the ID [infectious disease] physicians in the audience were all losing their [minds], real life manifestations of the Vince McMahon meme with each successive tidbit of social history that got revealed.”

“When he got transferred to our hospital from the community center, his son brought in a printed case report of Baylisascaris meningitis and told the intern, ‘I think my dad has the same spots on his brain.'”

“Case got written up — you can even see the dedication to the family at the end.”

Drug-Induced Lupus

A commenter with the username Drwillpowers shared rare patient self-diagnosis:

“I recently had a patient diagnose themselves with drug-induced lupus from propranolol.”

“I agree that they had what looked like a malar rash, and some other autoimmune things, but I figured it was just standard autoimmune disease. Not something drug-induced. Certainly not from propranolol of all things.”

“The patient was absolutely adamant that this is what it could be, and so I ordered the histone test. And by golly, they were right.”

“Maybe not as cool as some of these other ones, but I was definitely caught off guard by the positive diagnosis. And they did get immediately better upon cessation of the drug.”

“Back when I was in residency, my attending taught me that if a patient really truly asks for a test, and that test can’t hurt them, and there’s any rational justification whatsoever for ordering it, just order the test.”

“Like 97% of the time, the test comes back negative and the patient feels better, but every now and again I get one of these, and I get humbled by it.”

Sudden-Onset Crying

Finally, a commenter with the username dysmetric shared a story about a patient’s apparent brain tumour:

“Twenty-something years ago, after 6 months of sudden-onset crying for no reason (pseudobulbar affect) followed by slowly developing vertigo/headaches/nausea, I walked into my GP [general practitioner] and said, ‘I think I have a brain tumour.’ He laughed, said I was too young, then tried to diagnose me with benign positional vertigo [BPV]. I said it’s not BPV, grabbed on to the sides of my chair firmly and declared ‘I’m not leaving until you give me a CT referral.’ He did, and said”:

“‘Go get a scan in 2 weeks, if it hasn’t cleared up.’ I got the CT the next day, and was in emergency surgery to resect a large cystic pilocytic astrocytoma 2 days later.”

“The lunacy was how I knew.”

“I had suspected for a while because of the crying and the vertigo. The crying was intense, but I knew those symptoms weren’t reliable indicators and I mostly thought they might be associated with a brain tumour because I couldn’t establish any other plausible etiology. The vertigo had become very bad when I laid on my left side, but vanished entirely when I laid on my right.”

“The headaches and nausea emerged late, and they were the symptoms that gave me a decent cluster pointing to brain tumour. After 6 months of bawling for no reason I was at a psychological point that I was hoping it was a brain tumour, because that was preferable to being insane.”

Think Horses, Not Zebras

Joel Zivot, MD, MA, JM, associate professor of anesthesiology and surgery at Emory University and a senior fellow at the Emory Center for Ethics, told MedPage Today that, “Although zebras are really rare, they’re not impossible.”

Most people explain their zebra stories as coming from “a gut feeling,” Zivot said. However, he noted that most are the result of simple heuristics, or helpful decision-making shortcuts based on past lessons or experiences. Clinicians and even patients usually find those rare clinical answers from their experiences, even if they don’t remember when they learned them, he said.

While zebra stories can be exciting and rewarding for the individuals involved in those cases, in general, immediately thinking zebras is not sound clinical decision-making.

“Even in medicine, we’re motivated by an interesting story and interesting findings,” Zivot said. “But from a strictly analytical perspective, you should just pick the thing that is most likely based on the odds, and not the thing that is the most interesting.”

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