The Great Pretender

So, the other day, Dr. S is puzzling over a case. It's a min-pin with vague malaise. The dog vomits sometimes and seems lethargic. Other times it seems fine. This has been going on, waxing and waning, for several weeks. Last weekend it was sick enough that it was taken to the ER and put on fluids to combat dehydration and anti-emetics to treat vomiting. It seemed better after that, for a few days, but now it's sick again. The blood work is normal except for minor calcium and protein disturbances and a little azotemia (elevated kidney values). The X-rays are clean, and the CBC (complete blood count) are normal.

So, Dr. S - who has been out of school only four years, I must point out, to my 14 - is bouncing the case off me, looking for inspiration or other points of view. This is a smart move; sometimes we just get tunnel-visioned or stymie ourselves and get stuck. She runs past me the X-rays, the bloods, the symptoms. I look at the bloods; the liver is good, the renal values are indeed elevated, but that might be as a consequence of dehydration and vomiting. The calcium may be off because of the vomiting, or because of the protein being off (these often run together), and the protein could be off because the dog has been intermittently anorexic for several weeks now. Could be a lot of things: a virus, a toxin, a parasite, a foreign body, renal failure, pancreatitis. Lots of other things.

Or.... it could be Addisonian.

Now, here you will have to forgive me. When I was in school, they told us we might see Addison's disease once or twice in a 20-year practice career. I, however, look for it behind every tree and bush. The reason for this is that I got rewarded for it, somewhat memorably, right out of the gate. The experience has stuck with me.

It happened like this: At the U I attended, we had something called PBL (problem-based learning). This was a study group, six or eight students assigned per group based on our rotation schedule. In PBL we are presented with an actual case - something that has presented to the U in the last decade or so. We are provided the complete information - signalment (age, breed, gender), labs, X-rays, what have you. If the actual test wasn't run, they give us the result that would have been achieved had it been run. It's a good idea - it gives us a chance to try our diagnostic skills, the identification of unknowns, without putting the well-being of a live animal on the line. The group is run by a clinician - in our case, Dr. G, the King Of All Things Renal. Dr. G is a tall, Scandinavian-looking fellow, with prominent light-blue eyes and rosy skin and fair, thinning hair, and is completely brilliant and endowed with a dry sense of humor and a deadpan delivery that renders him a great deal more hilarious than if he had mugged for the laughs. His face has the gift of simultaneously being completely expressionless and inscrutable, yet somehow, at the same time, eloquently expressive. On this particular Friday afternoon, he has presented us with a 5-year-old male neutered black standard poodle. The dog has presented with weight loss, anorexia, vomiting. The physical exam is unremarkable, except for dehydration and mild pallor.

"So," says Dr. G. "What test do you want to run?"

"I think we should test it for Addison's disease with an ACTH stim," I say. "JFK had that, you know," I add primly. This I know because the previous evening, whilst studying, I'd been watching PBS. [Yes, I know that studying with the TV on is an idiot idea, because it's too distracting; but sometimes I just needed to have something non-academic on which to focus every so often, when I needed to pause my brain and let it process.] That particular night had been a JFK special, from which I learned that he had nearly died, in his young adulthood, from an undiagnosed case of Addison's disease. It's a rare condition, rare as hen's teeth, and it has an even rarer variant, the atypical Addisonian. The atypical is as rare amongst Addisonians as Addisonians are amongst normal animals. The atypical has none of the lab anomalies that one would expect to see on the normal workup, and has to be diagnosed via special labs.

Naturally, the rest of my PBL group laughed when I suggested this. Some of them laughed because of my manner, meant to be humorous. Others laughed because you just never see Addisonians. A few just shook their heads. Dr. G gave me a Look. It was mild, calm, ordinary, and simultaneously just a bit outraged, with a definite edge of Shut up, will you? to it. Ooops, I thought. Dr. G thinks I'm being silly and doesn't appreciate it.

"How do you know JFK was Addisonian?" asks one of my classmates.
"Saw it on PBS last night," I said.
"You don't normally jump right to an ACTH stim test," interrupts Dr. G. "Don't you think you'd like to run some other tests first?" he suggests, with a pointed look.
"Okay," I said brightly, "but I still want to do the ACTH stim."
"What if I tell you he has normal electrolytes?"
"Could be an atypical. ACTH stim."
"What about doing a CBC and a chemistry?"
"ACTH stim."
"What about X-raying the abdomen to look for the source of the vomiting?"
"ACTH."

Dr. G sighs. He gives me a look that somehow conveys exasperation, disgust, outrage and amusement at once. He hands over the test results. The dog has failed to stimulate. It's Addisonian.

"See?" I said, in the prim voice. I give him a sidelong look. He's shaking his head.
"Okay, now that Dr. H has ruined our PBL for the afternoon," he says to the group, glaring at me, "here's what you WOULD have found if you'd run the other tests." He passes out the lab data sheets, and then gives me an exasperated look. "You aren't supposed to guess it right off the bat," he says. "This is a difficult diagnosis, and most people miss it the first two or three times the dog presents, and a fair number of them die or go into severe crisis before they're diagnosed. They're rare, and I don't want you guys thinking you just go right to the diagnosis like that." He shakes his head. "Damn PBS."

As a result of this immediate success - which, it must be noted, can be credited to random good luck much more than any personal brilliance on my part - I have never forgotten that there is Addison's disease to look for, and that there are the rare lurking atypicals. I look for them always, and as a consequence, far from the one - or at most two - I should have expected to see by now, I have seen, as of today, a round dozen. Of those, only two were diagnosed before coming to our clinic; the others were diagnosed in our clinic. The very first one I diagnosed after moving to Alaska was an atypical (an even tougher diagnosis than the usual atypical, as the dog had a concurrent cardiac anomaly that afforded her far more than the usual degree of Addisonian mystery). Some of the ones diagnosed at our clinic were diagnosed by other doctors. In all honesty I can't say how much of that was because of me hopping around in the background saying "I bet it has Addison's disease, we should run electrolytes and do an ACTH stim." But you can bet your heiney that I WAS hopping around int he background, saying just that.

Flash forward to Dr.S's case.

I bet you know what I'm going to say.

"I bet it has Addison's disease. We should run an ACTH stim."
"Hmmm...." says Dr. S, musing. "That might explain a few things."
"I have to warn you, however, that if it IS Addisonian, I'm going to shamelessly take credit for the diagnosis," I add with a cheery grin. Dr. S laughs.
"If it's Addsionian, you deserve credit for the diagnosis," she says. "I wouldn't have thought of it," she said frankly.
"Well, it's rare," I allow, "and when you hear hoof beats, you should be looking for horses. This is a definite zebra. I think it's under diagnosed, though; I've seen nearly one a year since I graduated - all because of one twist of fate that had me watching PBS at just the right time."

So now flash forward to today. Dr. S shows me the bloods. The pre-stim cortisol should be over 80. It's one. The post-stim cortisol should be between 220 and 550. It's five.

Five. It's a wonder the dog is still alive.

The good news is that Dr. S had wisely started the dog on supportive care while pending the bloods, and the dog, while suffering some malaise, is stable. The further good news is that the meds have gotten a great deal less expensive in recent years, and our min-pin will live a normal life so long as she gets her meds. Had she not been diagnosed, she would have died.

Dr. S accords me my title of Queen of Medicine for making the diagnosis. I decide that we should BOTH be the Queen of Medicine. Because, in fact, it is an ass-kicking diagnosis, one that was missed by the other two doctors who have seen the dog, and even by the hotshots at the ER. We bounce around the clinic all afternoon with insufferable grins on our faces.

I love PBS.