Clinical Vignette that needs some differentials?

Question

A 28 year-old sewage-worker returns from a five-day hunting trip in Oklahoma with joint pain and swelling. He was in good health until he noticed knee pain and swelling three days ago. Since that time, he has also experienced pain and swelling in both wrists, and the right ankle. Two days ago he noticed an erythematous (red) rash with occasional pustules over his left wrist and left knee. He had a fever last night, and he had such severe night sweats that he had to change his bed-clothes. He has had a headache on and off for the past several years, but it seems worse now. He has a mild non-productive cough but no shortness of breath. He notes eating at a local restaurant one week ago where he had raw oysters. He has also indulged in some of the city’s best heroin and the pleasure that bear not speak its name (i.e., unprotected sex with prostitutes).

These usually take me 5 hours to figure out, so any help would be appreciated. :-)

This is the question that I have to answer: What are the diagnoses you are considering and what questions would you ask to evaluate each of these diagnoses? Please assign a probability to each of your diagnoses.

It's a med school homework question, so I'd have to be pretty detailed. :-) At least I don't have to do a write up on the physical exam this time.

So far, someone has suggested Lyme disease. That explains the fever, rash, and arthralgia, but not the cough or pustules.

Answer 1

Brucellosis is a zoonotic disease acquired by hunters and abattoir (i had to look that one up:)) workers, and is manifest by fever, night sweats, malaise, arthralgia, myalgia lymphadenopathy, and hepatosplenomegaly. Occasionally, arthritis.

Disseminated blastomycosis. Is this a hazard for sewer workers? I don't know. It can be associated with mild to severe pulmonary symptoms, skin and subcutaneous abscesses and visceromegaly. Also CNS manifestations.

His dalliences with women of dubious virtue could lead to gonococcal arthritis with similar manifestations. Could the pustules be chancres? Now for headaches. As a pediatrician, my experience with tertiary syphilis, even during a rotating internship in the inner city, is zilch. Twenty-eight sounds a bit young for that.

Eating oysters and being a sewage worker could predispose him to Hepatitis A. His heroin habit could expose him to risks of Hepatitis B. Neither of those cause all the symptoms he suffers from.

This is better than crossword puzzles for a retired grey doc. Let us know the answer

Answer 2

1

Answer 3

I don’t have the time or energy to do a thorough job for you, but I have some ideas that may help you. Remember that not all of the symptoms need to be from the primary disease. Don’t rule out a diagnosis that otherwise sounds pretty good because it doesn’t cause, for example, a dry cough – that may be from another source

The sewer is probably supposed to suggest ratbite fever (http://prod.hopkins-abxguide.org/pathogens/bacteria/aerobic_gram-negative_bacilli/full_streptobacillus_moniliformis.html) or maybe tularemia (http://www.idinchildren.com/200505/wyd.asp )

The hooker probably is in there to suggest gonococcemia.

The oysters and IV needles (assuming the heroin was injected) sound like red herrings. This isn't hepatitis or acute HIV or endocarditis

Hope that helps a little.

Answer 4

EDIT - I didn't mean osteomyeltis... I meant septic arthritis! http://www.emedicine.com/orthoped/TOPIC437.HTM

Scroll down to the pathophysiology and clinical bit, a bit of which I pasted below.

"Septic arthritis can be difficult to diagnose in the early stages of progression. Once purulence has developed and a bulging effusion is noted, diagnosis is made easily. Typically, the patient presents with fever and a joint that is hot, red, painful, distended, and has a markedly decreased range of motion. Restriction of movement occurs to active and passive attempts.

In young sexually active patients with fever, tenosynovitis, migratory polyarthralgia, and dermatitis, suspect N gonorrhoeae. The rash may appear as papules over the trunk and extensor surfaces of distal extremities that eventually can turn into hemorrhagic pustules. Women are more likely to develop gonococcal arthritis than are men.

In patients with a history of intravenous drug use (IVDU), suspect Pseudomonas."

I guess you'd ask him questions about trauma, about previous history of joint problems. And then the usual pain-related questions.

The fever = infection, and he also has joint problems... outting the two together would give joint infection.

Answer 5

I really hope you're not in med school because if you can't figure this out on your own how will you become a doc?!