Differential Diagnosis?

[MedStudentWanna]

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Sorry for this stupid question, but can someone tell me what this means and how it differs from a regular (the main?) diagnosis?

 

[indo]

A differential is the list of things a person could have based on their symptoms.

Ex: Sore throat
1. swine flu
2. chlamydia
3. strep
4. tumor
5. lupus
6. malingering

Usually you'll have to defend your #1 and talk about why the rest are less likely.

 

[pingouin]

Differential diagnosis is a list of hypotheses (or potential diagnoses) that explain the patient's symptoms. As you initially form a Ddx list, you'll start broadly thinking of multiple systems within the body that could be contributing to the disease. As you gather more information through the history, physical, labs/tests, and imaging, you should be able to rule up a few and rule down the rest until you arrive at the "actual diagnosis".

Of course, in real life it's not always that easy to find an actual answer, but if your school gives you something like that as an M1 they're just cruel. 😉


btw, Indo gave a great example of what I was talking about regarding multiple systems: he covered infection (both viral and bacterial), neoplasm, autoimmune, and psychiatric in one list. 🙂

 

[spicedmanna]

Sorry for this stupid question, but can someone tell me what this means and how it differs from a regular (the main?) diagnosis?

It's your working list of possible diagnoses based on a patients presenting signs and symptoms. Your list is going to include your most likely diagnoses at the top, but also includes serious ones you want to rule out, and also less likely ones, as well. If you don't think of it, you might miss it. Your list helps guide your workup. As you run studies and get results back, you begin to rule things out and confirm, etc.

For example, let's say you are called to consult on a 23 y/o G1P1 woman who presents to the ER with 8/10 diffuse lower abdominal pain that is most significant in the RLQ and dyspareunia for the past two days. As the ER reports this to you on the phone, what possible diagnoses are you thinking about? You might be thinking of appendicitis, ectopic pregnancy, PID, cervicitis/salpingitis, ruptured luteal cyst, adenexal torsion, endometriosis, pyelonephritis, intestinal obstruction or incarceration, kidney stone, or even constipation, etc. So thinking about all this, what would you do for a workup? Of course you start with a good H&P (you can learn a lot from this), run some blood work (CBC + diff, lytes, BUN/Cr, LFT, CRP, beta-hCG) and a U/A, do a pelvic exam and culture for GC/Chlamydia/BV/TV, and consider an abdominal CT, abdominal U/S, and transvaginal U/S. Based on information from the H&P, lab work and studies as they are coming in, and your clinical judgment, you begin to rule things out (most serious first), consult with specialists, consider admission to the hospital, and maybe even begin treating empirically as confirmatory tests are pending.

I'm pretty new to the whole process, too, but this is basically how it goes.

 

[spicedmanna]

Actually, it might have been easier for me to have suggested that you simply watch an old episode of House. While it's exaggerated, it can help elucidate some aspects of your question.

 

[MedStudentWanna]

Thanks guys!

 

[Tiger26]

Differential diagnosis=mental masturbation (especially on medicine)

 

[indo]

Differential diagnosis=mental masturbation (especially on medicine)

I vote for this one.

 

[AndyEmmDee]

Forming a list of potential diagnoses...sounds difficult...I love challenges =)

Can't wait to get out of the lecture hall and into the real world.

 

[Ibn Rushd]

It's your working list of possible diagnoses based on a patients presenting signs and symptoms. Your list is going to include your most likely diagnoses at the top, but also includes serious ones you want to rule out, and also less likely ones, as well. If you don't think of it, you might miss it. Your list helps guide your workup. As you run studies and get results back, you begin to rule things out and confirm, etc.

For example, let's say you are called to consult on a 23 y/o G1P1 woman who presents to the ER with 8/10 diffuse lower abdominal pain that is most significant in the RLQ and dyspareunia for the past two days. As the ER reports this to you on the phone, what possible diagnoses are you thinking about? You might be thinking of appendicitis, ectopic pregnancy, PID, cervicitis/salpingitis, ruptured luteal cyst, adenexal torsion, endometriosis, pyelonephritis, intestinal obstruction or incarceration, kidney stone, or even constipation, etc. So thinking about all this, what would you do for a workup? Of course you start with a good H&P (you can learn a lot from this), run some blood work (CBC + diff, lytes, BUN/Cr, LFT, CRP, beta-hCG) and a U/A, do a pelvic exam and culture for GC/Chlamydia/BV/TV, and consider an abdominal CT, abdominal U/S, and transvaginal U/S. Based on information from the H&P, lab work and studies as they are coming in, and your clinical judgment, you begin to rule things out (most serious first), consult with specialists, consider admission to the hospital, and maybe even begin treating empirically as confirmatory tests are pending.

I'm pretty new to the whole process, too, but this is basically how it goes.

Such an awesome post. Thanks!