Septic Arthritis

00:01 In rheumatology, I will take a look at a septic arthritic condition.

00:06 Something that you want to keep in mind is, what's the difference between septic arthritis and you ever heard of reactive arthritis? So what is septic arthritis? Now, seriously, this is an emergency.

00:18 Acute inflammatory, asymmetric, monoarticular. You're going to have this perhaps the knee, swollen, red, and it's inflammatory.

00:29 In other words, it would be purulent, the synovial fluid will be when you do arthrocentesis.

00:35 But why is it a medical emergency? Because it may only take hours for disinfection to completely destroy the cartilage.

00:43 And then once that cartilage has been damaged, please note that oftentimes, that this is a permanent manifestation. Not good.

00:51 Now, I mentioned purulent synovial fluid. So, what does that mean to you? So here's a condition in which the synovial fluid… And you might find the WBC count to be > 50,000.

01:03 Yes, you heard that correctly; 50,000.

01:06 A normal WBC count, well, in your serum should be between 45 to 11,000.

01:12 Here, it could be as high as 50,000.

01:15 In osteoarthritis, we call that non-inflammatory because if you did an arthrocentesis and the synovial fluid was < 2000, then you'd call that non- inflammatory, correct? Now, apart from the rapid nature of all this, the associations are important.

01:36 Then diabetes, skin infection secondary to neuropathologic changes could be present.

01:42 In drug users, obviously here looking at the site of injection, and in addition, you're also worried about endocarditis, aren't you? For example, tricuspid valve issues.

01:56 In a young patient who comes in with that monoarticular inflammatory painful, red knee, you're thinking about gonococcal.

02:07 Continue our discussion of nidus of infection.

02:10 If your patient comes in and he is an African-American boy and has sickle cell disease, well, you know that in sickle cell patient, the common organism that then causes osteomyelitis will be Salmonella.

02:23 And that's what you might be thinking about here. Keep that in mind, though.

02:27 The reason I want you to keep that in mind is if your patient has back pain, and is HLA-B27 positive, and you find something like Salmonella, then you might be thinking about reactive arthritis. But here, this is in a setting of sickle cell disease, Salmonella.

02:45 In trauma, look for Staph epidermidis.

02:49 In immunosuppressed patient, and you're worried about septic arthritis in general, from whatever type of bacteria, perhaps.

02:57 Patients with underlying disease, especially rheumatoid arthritis.

03:01 Patients with prosthetic joints are often susceptible.

03:06 The 2 main groups of organisms, however, with septic arthritis, you're going to focus on the following in terms of category. Now, so as I told you earlier, the nidus of septic arthritis, prior discussion, if the patient came sickle cell disease, diabetes, and so forth, then you might be looking at other organisms. But, in general, you'll divide this into gonococcal, non- gonococcal type of septic arthritis.

03:33 This has nothing and may not have an association with back pain, and does not have an association with HLA-B27.

03:43 As soon as you start hearing about HAL-B27, then you're thinking about, "Oh, what type of arthritis dealing with organisms," then you might be thinking about reactive arthritis, isn't it? It used to be called Reiter, remember that? So we'll discuss Reiter in detail, but it is no longer called Reiter in current day practice.

04:04 It is called reactive arthritis.

04:07 Our discussion here is what? Septic arthritis.

04:12 We're dividing this into gonococcal and nongonococcal.

04:16 Under nongonococcal, staph would be common.

04:21 Group A beta streptococcus, we're talking about streptococcus pyogenes.

04:28 If it is gonococcal, you think about that young patient that comes in and what's my presentation? Monoarticular, asymmetrical, inflamed knee, and it feels warm.

04:39 And you know it's inflammatory because that synovial fluid is going to have > 50,000 WBC. Is that understood? Signs and symptoms. Here we go again.

04:52 Acute monoarticular joint pain, red, fever, septic.

04:57 Mimics gouty, but has nothing to do with uric acid crystals, correct? Both are inflammatory type, no doubt, but this is obviously septic.

05:06 Both septic in gouty, will occur at the same time, that's a possibility.

05:13 And depending on the drug, the severity of symptoms would be, well, a little bit different.

05:18 So, if you're thinking nongonococcal and you're thinking about staph aureus, oh my goodness, his thing is so aggressive.

05:23 Remember, this is an emergency.

05:26 If you're not careful, and if you're not paying attention, and you're not doing due diligence, that cartilage is going to be destroyed and this patient then goes into permanent issues.

05:37 Then gonococcal, think gonococcal if the patient is young, present as such.

05:44 Young sexually active patient, and here, acute monoarticular type of pain that you would expect.

05:51 And you would assume, as a clinician, that it's a gonococcal type of septic arthritis, unless proven otherwise.

05:59 Also keep in mind, in labs, u-neisseria species at times can be rather difficult… fastidious organism.

06:07 It can be difficult to identify.

06:09 So just because it comes back to be negative, but the patient is presenting and a young patient, you still need to aptly confirm and rule out gonococcal.

06:19 Slower onset of symptoms, usually, still, days.

06:22 So, we're not talking about months here, we're talking days, so still relatively quick.

06:26 Whereas, if you're thinking staph… The patient may have symptoms of a genital infection if you're thinking gonococcal.

06:36 Asymptomatic, well, here, if you're thinking about periarthritis- dermatitis syndrome.

06:41 Now, what that means is the following.

06:44 Let's say that your patient has gonococcal- type of septic arthritis, but you don't find purulent arthritis. What does that mean? You don't find the synovial fluid to have WBC count < 50,000.

06:57 Then you're not going to look for the following triad with gonococcal. You're ready? The triad. Well, periarthritis. What does that mean? In the hand, you're thinking tenosynovitis, number 1.

07:09 When you're thinking derm, you're thinking about issues with pustules.

07:14 Keep that in mind.

07:15 And there might be joint pain called polyarthralgia.

07:19 So we have polyarthralgia, we have issues with the hand with tenosynovitis, and lastly, there might be pustules, including a derm.

07:29 Now, the triad, please, for gonococcal.

07:31 If you do not find purulent arthritis, look for that.

07:34 Very important.

07:37 Next, well, seen in neisseria meningitidis would be what? The rash. So, in general, the rash, as I was telling you earlier, with the pustules, could be seen with gonococcal, but in addition, may also be seen with the neisseria species meningitidis, keep that in mind.

07:57 So both of these may be taking place concomitantly.

08:02 With gonococcal arthritis, positive sexual history, as we talked about.

08:08 In a lady, the culture, cervical, urethral, pharyngeal, rectum, all different areas in which there might have been introduction of gonococci.

08:20 Gonococcal, hard to culture, as I was telling you earlier, and so, therefore, if inappropriately performed in the laboratory, it may then give you a false negative, keep that in mind.

08:32 End joint aspiration needs to be done.

08:34 As I told you, you could find that purulent arthritis.

08:37 And if you don't find it to be purulent and you don't find the high WBC count, you're looking for that triad, of what again? Tenosynovitis of the hand.

08:47 If it's derm, then you're thinking about pustules, and you're thinking about polyarthralgia, which means joint pain in many joints.

08:57 Nongonococcal.

08:59 Give me the 2 major organisms here.

09:01 They included staph, credibly, incredibly aggressive.

09:05 The other one might be strep.

09:07 So here, you're going to find, once again, a purulent type of arthritis and a synovial fluid will have a WBC count > 50,000.

09:15 If you're suspecting to be nongonococcal, obviously, obviously, your staph and strep will then be Gram stain positive and gram-positive anything.

09:24 If patient received antibiotic prior to aspiration, well, then this may give you a false negative, correct, in general. Kind of like the same theory and discussion that you would have with urinary tract infections, as well.

09:37 Blood cultures for nongonococcal.

09:42 Management of gonococcal would be ceftriaxone IV, followed by oral. It's important that you attack and combat the septic arthritis.

09:53 If it's a nongonococcal, then gram-positive antibiotics, such as vancomycin.

10:01 If it's nongonococcal, require drainage, for sure, needle aspiration, surgery drainage, and ortho consult, keep that in mind.

10:10 You need to be aggressive in how you manage a patient with nongonococcal. Remember, with gonococcal, it may buy a little bit more time, but we're only talking about, maybe, days more.