Really important clinical question here.
A 32-year-old Caucasian female is referred to a gastroenterologist
by her family physician for eight months of abdominal pain,
foul smelling diarrhea that is floating, bulky stools, weight loss, and macrocytic anemia.
Her personal history is relevant for allergic rhinitis.
Physical examination shows grouped erythematous, papulovesicular lesions on her arms, torso and abdomen.
Which of the following is the most appropriate approach to the management of this patient?
Answer choice A: Amitriptyline;
Answer choice B: Octreotide;
Answer choice C: Lactose-free diet;
Answer choice D: Gluten-free diet;
Answer choice E: Methylsergide maleate.
Now, take a moment to come to your own answer choice before we go through them together.
Okay, this is a very important question.
Very commonly on USMLE, you're going to be seeing images.
Now, you don’t always have to know what they are by heart but it always helps.
Now, this is an internal medicine question and it’s gastrointestinal.
You can see here the patient’s coming in abdominal pain, diarrhea, bulky stools, and they even have anemia, so it’s GI.
Now, this is a two step question.
First thing we gotta do is figure out the diagnosis
and second thing we gotta do is figure out the management of that disease after we diagnosed it,
and the stem here is absolutely required.
We got to once again dissect the stem down, take out the key components
and figure out what we're dealing with for diagnosis and then come to a management strategy.
So let’s do that.
Step one, let’s determine the diagnosis.
Now the chief complaint here of this patient really is chronic abdominal pain with accompanying GI symptoms.
The patient did say she had eight months of abdominal pain
and the GI symptoms when you really look at them in the question stem, they really are suggestive of malabsorption.
The patient has foul smelling diarrhea that’s floating -- the floating is because of high fat content.
Bulky stools because not a lot of content is being absorbed by the body so it’s being lost into the stools
and the weight loss is because of malnutrition and malabsorption causing weight loss.
And also the blood results that are commented in the question stem are also consistent with malabsorption.
The patient has a macrocytic anemia.
Well, the anemia itself is the low hemoglobin, but the macrocytic component is the very large red blood cell.
Now the most common cause of a macrocytic anemia is a deficiency
or lack of absorption of vitamin B12 which can cause pernicious anemia.
Now, there really is quite a wide differential diagnosis just looking at the question stem alone.
You could have prolonged antibiotic use, Celiac disease, Crohn’s, chronic pancreatitis,
cystic fibrosis, lactose intolerance -- all of these things could cause the clinical presentation of the patient in the question stem.
Now, this is where I was saying it’s really important in USMLE you use the picture that’s given to you.
There’s a reason they're giving it because without the picture, it really is confusing.
It could be many things like we just mentioned.
Now, if you look at the picture, they're showing you a dermatological lesion.
They call it grouped-erythematosus papulovesicular lesions and they tell you it’s on the arms, torso, and abdomen.
Now, what that looks like to me is herpes.
Now, but it’s on weird places, it’s not where you would expect herpes.
I mean if you were to name that, you might call that dermatitis herpetiformis, right?
It looks like herpes of the skin but in weird places.
Now, that’s why it’s really important to know what you're looking at for pictures
or know the dermatological words we use to describe different skin lesions.
Now, in this case, this is dermatitis herpetiformis and it’s associated with gluten intolerance.
The exact pathophysiological mechanism here really isn't known,
but we know it’s associated with deposition of IgA in the skin.
Now, to come to the diagnosis, what condition causes all these GI and malabsorption syndromes with this skin finding?
The answer is Celiac disease.
So with the image we were able to take a broad differential and really narrow it down to Celiac’s disease and to know the diagnosis.
Now, the next step is we’ll how do you treat Celiac disease and of the answer choices listed really a gluten-free diet,
Answer choice D is the clear one, because people with Celiac has a gluten allergy.
So, let’s go through the answer choices,
talk about how you could have eliminated the other ones or just directly gone to the right answer.
Now, once we figured out this patient had Celiac disease we know it’s an autoimmune condition
which is caused by hypersensitivity to gluten, a protein that’s commonly found in wheat, barley, and rye.
Now, the clinical manifestations of someone with Celiac disease is foul smelling diarrhea,
steatorrhea, malabsorption which will lead to both water and fat soluble vitamin deficiencies as well as skin manifestations
what’s called dermatitis herpetiformis that you see in the image
that’s actually cause by IgA deposition in the skin, very important to memorize that.
Now, the diagnosis of Celiac disease can actually be made through laboratory testing for IgA amino acids,
you could do a small bowel biopsy to look for shortened villi or as we call them blunted villi and you can even do a gluten diet test.
Now the management of Celiac really is a gluten-free diet to replete the nutritional deficiencies that they have
and most guidelines, very important, this is modern, memorize,
recommend pneumococcal vaccination as actually Celiac's disease has been associated with hyposplenism.
Now, given that Celiac is an autoimmune reaction to gluten, we tell the patient to simply avoid it.
Now, it’s actually a pretty common disorder, one out of every 1 to 200 people are actually affected globally.
Now, like I said, you could do a small bowel biopsy to diagnose this condition
and what you're gonna be looking for is villous atrophy which will then obviously lead to malabsorption
cuz the villi can't be there to absorb and that will eventually lead to anemia.
Now, patients with Celiac really do have a wide symptomatology
but overall, they're gonna have GI, malabsorption related and dermatological complaints.
Now, usually, this was a 32-year-old patient,
usually it’s diagnosed in childhood but it can come and present at any age
and of course the gluten-free diet is how we wanna treat it.
But before we leave Celiac’s, take a quick look at that picture again.
The dermatitis herpetiformis really does look like herpes lesions
and you don’t have to memorize the fancy term of group erythematous papulovesicular lesions unless you want to,
but if you as a doctor can look at the image and say, hey, that looks like herpes,
but this patient has GI stuff, you can come to the Celiac’s diagnosis
but for you to know it’s important that this skin lesions are actually itchy to the patient and they're fluid filled blisters,
and again it’s caused by the IgA deposition in the skin.
Now let’s look at the other answer choices.
Now, you can eliminate a lot of them once you figured out its Celiac disease,
once you know the diagnosis well, boom!
You can go straight to gluten-free diet.
But what if you couldn't figure out the diagnosis? How could you eliminate?
Now, Answer choice A is Amitriptyline.
Now that’s a tricyclic antidepressant and we actually do use that for irritable bowel syndrome
which is a chronic condition characterized by a constellation of GI symptoms
but very much these patients will have both diarrhea and constipation
and intermittent cramps in the absence of real any organic abnormality we can find.
So, amitriptyline for irritable bowel, this patient has many things
that we can actually find on exam so this is not irritable bowel much more Celiac's disease.
Answer choice B being octreotide. Now that drug you used in carcinoid syndrome
which is a paraneoplastic syndrome caused by carcinoid tumors
and that will primarily be derived from the ileum and the appendix
and the carcinoid syndrome is actually when the tumor is secreting serotonin and kallikrein
which then leads to the patient complaining of flushing, diarrhea, heart failure and bronchial constriction.
So for this, we give octreotide, a somatostatin analog to reduce this endogenous serotonin
and kallikrein secretion to control the clinical symptoms.
Now Answer choice C, a lactose-free diet, is what you would prescribe someone with lactose intolerance.
And they can have a deficiency or complete absence of the lactase enzyme.
Very important, lactase is an intestinal brush border enzyme that degrades lactulose,
excuse me, lactose into glucose and galactose, you have to memorize that.
USMLE loves to let you know, that lactase is a intestinal brush border enzyme
and they also love testing that lactose gets broken down to glucose and galactose,
but this patient doesn’t have lactose intolerance,
they have skin findings that we would not expect and you don’t really expect that much malabsorption.
Now, lastly, we have Answer choice E, which is methylsergide maleate.
Now a lot of you won't know what this is and you may be tempted to pick it on the exam
because you're like, I don’t really know what's going on, this sounds complex and fancy -- I’ll just pick it.
This is a common distractor.
Now this medication is used in the management of also carcinoid syndrome and serotonin syndrome
but they were really important adverse effects with this medication
which cause retroperitoneal fibrosis and retropulmonary fibrosis so it’s not really used anymore,
but this is a common distractor seen on USMLE exams for you to pick something that you're not familiar with and that sounds fancy.