Dr. Erica Lawson presents "Atraumatic Limp – Navigating Rheumatologic Condition" at the UCSF Pediatric Musculoskeletal and Sports Medicine Conference 2023 in Berkeley, CA.
So I'll be introducing our next speaker. So we'll switch gears a little bit um from biomechanical MS K conditions to um uh systemic um ideology. So, uh our next speaker is Doctor Erica Lawson. Uh Doctor Lawson is a pediatric rheumatologist here at U CS F. She completed her pediatrics residency at Seattle Children's and then fellowship in pediatric rheumatology at U CS F. Um She has a special focus on adolescent and young adults. Her research interest center on improving long term outcomes and access to adult care for individuals who develop rheumatic disease in childhood. She also serves as the fellowship program director for pediatric rheumatology. So, welcome, Doctor Lawson. All right. Thank you. Um So, hi, thanks so much for having me today. Um We are gonna be talking about some different causes of a traumatic limp. Um So I'm gonna start off just talking a little bit about the general approach to these patients. Um not getting tuned into the weeds because I know that um others are covering different aspects of this topic today. Um And I'm gonna spend the majority of our time talking about juvenile IOP paic arthritis um with a little bit of time also on juvenile dermato uh dermatomyositis and systemic lupus. All right. So what patient comes in with an a traumatic limp? What do you want to know important questions? How long from, especially from a rheumatologist perspective, how long has it been going on? Our conditions are chronic? So, things that have been happening for a long time make us think about rheumatic diseases. Um It's really important to get very specific with the location of the pain patients will come in and be like my leg hurts, my foot hurts where so need to get them. Um you know, to be very specific. So we have a sense is this in the bone, is this in the joint? Where is it going on? Um Is there any weakness present? Could this be a muscle problem? Um Of course, you want to get your trauma history and any kind of sports history um that might suggest an overuse injury. Um and what makes it better? So things that uh often help in rheumatic diseases can include nsaids and heat, what makes it worse? Often can be cold or impact activities um when pain is worse. So, rheumatic uh causes of pain classically are associated with morning stiffness. And that's one of the most important questions I ask. Um night pain. On the other hand, can be um suggestive of growing pains or can be a red flag for more serious condition. So that's important to ask about as well. Um And then numbness and tingling might take you down a different route. Um in terms of the ideology of your pain, things like amplified pain or um a neurologic condition. Other important questions. So, being a rheumatologist, I want to know about constitutional symptoms. Is there fever, is there weight loss? Is there a recent viral infection that might suggest a post uh infectious ideology um or a recent bacterial infection. Um Has there been any camping or tick bites? Lyme arthritis is something we see, especially in our patients who live in the North Bay. Um And so when I see a patient with monoarticular arthritis, um I always want to send the lyme um, oral or nasal ulcers are important. Uh If you're thinking about lupus and then always also important to ask about family history of autoimmune disease when a rheumatologic condition is on your radar. Um As you know, a lot of these conditions do run in families and if there's a strong family history of autoimmunity, that's gonna increase my index of suspicion. Um So what I do on my physical exam other than the usual comprehensive rheumatology joint exam. So I want to make sure that I'm taking a look at their gait. If they're weight bearing, want to do a good examination of the skin to look for any unusual rashes, including the mouth and the nose. Sometimes there's mucocutaneous findings that the patients aren't aware of. Um, you want to look for any tenderness in the back, um, especially over the secret joints. Um, and finally, if there's a painful extremity, especially in a young kid, as you all know, you want to examine that last. Um, so go to the painful place last because, um, having a calm child really increases the amount of information we can get out of our exam. Um, for me, when I'm doing a detailed joint exam, once the kid gets freaked out or I hurt them, sometimes the exam is just done, especially in a young kid. Um So and there's a lot you can do before you even get in there with your hands with just your eyes. So I want to look at both hands, side by side, knees, side by side and look and see. Is there any asymmetry there? Um swelling can be hard to identify. And so looking for differences between the two sides can be super helpful. Um I want to see if any of the joints are warm, especially the knees. So knees should always be a few degrees cooler than the shin. So that's uh an easy thing to check for. Um And then starting to gently palpate for any kind of tenderness or effusions. You want to check your range of motion. And then when I have a patient from a rheumatologist perspective, coming in with a say example, swollen right knee, I'm gonna still check every joint because many times they've noticed the knee because that's maybe what's hurting the most or looks the most impressive, but I might find a little bit of ankle swelling or find that there's pain on inflection with the other knee. So important to check it all. Um, so I mentioned already normal joints should be cooler than the adjacent limb. This is an especially helpful finding when you're looking at the knee. Um, a lot of times people, you know, when I, when they um think about arthritis, they're like well red joints, but in chronic arthritis, um erma is actually pretty uncommon. So if I see a really red joint, especially if it's, you know, pretty quick onset severe pain, I think about as septic arthritis, but we don't see it as much in rheumatologic conditions. Um and then joint swelling can be due to increase fluid, but also synovial hypertrophy. So not all swollen joints feel the same. Um when there's a lot of fluid, often it has more of a water balloon feeling. Whereas um arthritis that's been going on for a really long time, often there's really significant synovial hypertrophy and it feels kind of more dense in there. Um So different ways that you can elicit joint pain depends on the joint, but a couple um places that are helpful and important um as you can see over on the picture here. So, pain on inflection um of the knee is commonly seen with knee arthritis, um with a wrist you often have a limitation on extension but pain on flexion. So those are some helpful things to look for. Um arthritis, pain also is typically not super severe. Um And then another thing you'll notice is arthritic joints just don't move as smoothly or um as easily as a normal kid's joint. So that's another finding. You might not, you can range it, but it just seems a little stiff. Um And you want to of course, be looking out for those extra articular manifestations like a fever, a rash, red or painful eye. All right. So let's talk a little bit about J I A. Um How do you define it? It's arthritis in one or more joints and in order to be juvenile, you have to have onset of symptoms um before your 16th birthday and it has to last for at least six weeks. So this is really a chronic condition and it's a diagnosis of exclusion. So you need to rule out infection, malignancy trauma. You need to think about other autoimmune conditions like lupus. Um and reactive arthritis is another possibility. Um and juvenile idiopathic arthritis is really a waste basket term. So there are seven different subtypes of J I A, some of which are quite different from each other. And I'm gonna focus today really on the conditions that um can present more with an a traumatic limp. Um But we have olive articular J I A which is 1 to 4 joints and then polyarticular is five or more joints. Those patients can be either rheumatoid factor positive or rheumatoid factor negative. And we'll talk a little bit about the differences between those. Um You have systemic J I A which I'm not going to get into in detail today. But uh these are kids who present quite sick often with fever rash, seis, lymphadenopathy, HEPA and very elevated systemic inflammatory markers. So they're really very systemically ill. Um enthesitis related arthritis care um is the juvenile onset form of aloin spondilytis. So, you have sacred that uh axial skeleton involvement. Um psoriatic arthritis can be seen um in the presence of psoriasis. But you can also get a diagnosis of psoriatic arthritis with um findings of two of the three of nail pits, dactylitis or a first degree family history of psoriasis. And then finally, undifferentiated is if they don't fall into any of these categories or they actually meet criteria for more than one. So let's talk a little bit about the difference between normal and inflamed joints. So here you can see the normal joints you have this nice, smooth. Oh I'm just seeing how I would be good if I had a pointer. So I was hoping you guys could see my uh I'll use it if I have one, a lot of times you can see the little mouse but on this one, you can amazing. Thank you. Cool. OK. Much better. So, here you have this nice smooth cartilage, there's some fluid in there but not a ton. Um Whereas this inflamed joint here, you get, um, this really thickened synovium, this thick inflamed uh fluid and there's more of it. And then, um, chronically, you can start to get thinning of the cartilage. And you can see this cartilage is no longer smooth. And then you have your findings that are really very specific to Children specifically bony overgrowth. So kids who are growing when they have an inflamed joint, um the ends of these bones will become larger. And so you'll see the kids who have chronic arthritis often have these big sort of knobby knees. And even when all the inflammation is gone, the bony development is different. Um And this just, it shows some pictures where we see enthesitis um and enthesitis related arthritis and common spots here. Um And these can be sometimes a little bit difficult to tease out from o uh overuse injuries. So, red flags for that are a lot of morning stiffness and then um tenderness in multiple locations. Um So what causes J I A? We still don't have a great idea of the detailed pathogenesis, but we know it's an autoimmune reaction to the joint tissues. We also know there's some genetic predisposition um but it's not a straightforward Mendelian inheritance. Um And we do know that the H L A B 27 association um in, in isis related arthritis is particularly important Um And then there are factors that in the environment that may be triggers and may be protectant. So we see all the time patients who present with juvenile arthritis following an infection. So there's something about an infection that it seems in kids who are predisposed to autoimmunity can tip this off this activation of the immune system. Um There's also been studies demonstrating associations with maternal smoking. Um and protective factors can include breastfeeding and adequate vitamin D. Um I'm not gonna spend a ton of time on the differential diagnosis because again, other folks are covering these topics today. But the things that you should also be thinking about when you're considering J I A um fall in the buckets of infectious malignancy, um mechanical or noninflammatory and rheumatologic. Um And you can take a quick look at these guys. All right. So if you're thinking about J I A, what kind of labs should you order? Um It's important to remember that arthritis is a clinical diagnosis. It is not diagnosed based on labs, but they are helpful and can definitely be useful if you order the right ones. Things to keep in mind at baseline. 10% of the population has a positive A N A and 10% of the population has a positive H L A B 27 not all those people have lupus or arthritis. We'll talk more about that. Um, antibodies also can be transiently positive especially after infections. Um So you guys sometimes take those with a grain of salt as well. Um Where labs can be really helpful is to categorize the type of G I A. So, a rheumatoid factor, positive arthritis and H L I B 27 positive arthritis. Um and then really high inflammatory markers, not only points you in the direction of a rheumatic condition, but can also help to predict the severity and guide treatment. So, should I order that A N A? There are two uses for an A N A test in a patient who you think might have J I A. First of all, if the A N A is negative, that rules out an autoimmune connective tissue disease like lupus or mixed connective tissue disease. A positive A N A doesn't mean you have Lubis but everyone with Lubis has A has a um positive A N A and in oig articular J I A. So patients who have four or fewer joints, um we'll talk more in a minute about U V IIS which is the eye inflammation that's often seen in patients with J I A and A positive A N A in these patients predicts a higher risk of U V IISS. So that's another time when it's useful because we're gonna screen those patients more often for eye inflammation. However, a positive A N A does not increase the likelihood of AJ I A diagnosis in a patient with joint symptoms. So the way to not use an A N A is when your patient has joint symptoms and you're like, I'm gonna just check the A N A and if it's positive I'll send them to the rheumatologist. This stuff is confusing. I get it. So, and if you don't think about it every day, it's hard to remember. Um So what about rheumatoid factor? When do we use that? A positive rheumatoid factor can predict severe J I A and help to guide treatment choices. And it's most useful in kids who have polyarticular disease. So five or more joints including large and small, I mentioned it can be transiently positive and a true positive actually requires two positive tests at least 12 weeks apart. Um If the tighter is higher, that's also catches my attention a little more and is more likely to be a true positive. Any time you're ordering an R F, you should also order AC C P or cyclic cried peptide. Not everybody's familiar with this, but it's another antibody that basically functions the same as an R F. Some patients will be R F positive, some will be C C P S positive. Some will be both or neither. All right. So question what proportion of all kids with J I A are rheumatoid factor positive. I'm gonna ask for a little audience participation. Um Raise your hand if you think it's a, how about B 50 to 60% C 30 to 40% a few more there. OK. D 15 to 20% right now, we got some more. How about E 5 to 10%? OK. Seems like D is what most people think, but it's actually e so positive rheumatoid factor is pretty uncommon in kids with J I A. So in summary, don't use an A N A or rheumatoid factor is screening tests for J I A. Look at the patient if their joints are swollen or stiff or they have elevated inflammatory markers or if you're just worried, send them to the rheumatologist. All right. So what are the most useful initial labs? The three things I would say if you're gonna get anything CBC with differential set rate and AC R P. So you, you're looking for elevated white count, anemia, a normalcy anemia that looks like anemia, chronic disease, elevated platelets, high C rate, high C R P. All of those are indicators of inflammation. Um in patients with lupus, you can sometimes see a diff slightly different set of findings. So those patients can have Leuco penia um thrombocytopenia and then they actually often have an elevated set rate with a normal C R P. Um So some things that can kind of start to point you in the right direction as to what's going on there. But there's some other labs that can definitely be helpful. So I get AC MP on just about everybody on my first pass as well. Um because I'm often gonna be starting scheduled N A. And so I want to make sure their renal function and their hepatic function is normal, especially in a kid who's never had a reason to have these things checked before. Um We talked about the A N A for UBI Iis risk stratification or if you're worried about lupus rheumatoid factor or C C P, if it's a polyarticular presentation is helpful, we talked about lyme testing if it's oligoarticular arthritis, especially one knee. Um and H L A B 27. If there's family history or concern for enthesitis related arthritis, um If there's fever rash, the kiddo is really sick and has arthritis. Think about systemic G I A labs. Um I often get a vitamin D level on the first past two because um if it's low, I'll supplement and I often if, if they present with enough arthritis that I think that the writings on the wall that they're gonna need immunosuppression, I'll check um a quant of Ron while I'm drawing blood. So when do I need to test the joint fluid as you all know, any time you're thinking about infection, a culture of the joint fluid is critical. Um And the patients to think about that are those with acute onset of symptoms, severe pain and fevers. But in a patient who's had really chronic arthritis with more stiffness than pain, um especially in multiple joints. It's actually not that helpful. The fluid is inflammatory whether there's an infection present or J I A and patients with J I A can actually have greater than 100,000 whites in their synovial fluid and low glucose. So it's really the culture that you need to hang your hat on. Um So only useful if you're worrying about infection. Um x-ray can be helpful keeping in mind that it's not a good test for soft tissues but can show mostly findings consistent with longstanding arthritis. So things like periarticular osteopenia, bony erosions, joint, space narrowing. Um And this picture here, you can see there's a fusion here of these carpal bones. So this is pretty advanced, um a few other findings. So you can sometimes see soft tissue swelling. Although that's a little harder to interpret. Here's some more pictures of periarticular osteopenia. This is a really terrible carpal fusion. Um You can see erosions and narrow joint space here in the shoulder and in this knee. So what about MRI? MRI is helpful when you really want to confirm the diagnosis and it's a joint, either that you can't examine well, like a hip joint or just your exam is equivocal. Um So, MRI, in contrast, x-ray gives us that beautiful picture of the soft tissues. So you're gonna be able to see your effusions, you're gonna be able to see that hypertrophic inflamed synovium. You can also diagnose Sais, which is another joint that's difficult to examine. Well. All right. So let's move on to some cases, um, starting with a two year old Caucasian little girl who presents with two months of limp. So, what do you want to know? Mom tells you that limp is worse in the morning and she's not complaining about pain at all. She's sleeping well, she's eating and growing well past medical history and family history are unexciting. Um, and you check some labs and they are also, for the most part unexciting. She has a low, tighter positive A N A negative lyme, normal CBC A normal SU and C R P. All right. So what subtype of J I A is this? We have our little girl here wearing her really cool 19 seventies dress. She's got a big knee here and you'll notice she's kind of standing a little bit sideways. This is oligoarticular J I A. What common complication of J I A does she have? So you can see that she's standing again a little sideways. This knee is kind of bench. She has a leg length discrepancy. Um And what is the most important thing to do next? She actually needs to see an eye doctor because the worst thing that can happen to these kids with olive articular J I A is that they have U V I s and you don't catch it. Um So she needs a slit lamp exam to rule out U V I S. So I go articular J I A again, four joints or less. It's the most common subtype representing about half of all J I A. And the really nice thing is that this is the type you can tell parents that it is most likely to go into remission. So a lot of these kids um they will have this for a little while when they're young and then eventually it will go away forever. Um Peak age of onset is between two and three. But I would say, you know, up through elementary school is not uncommon. Um and more common in Caucasian kids as opposed to Black Asians or Latinos, um uh often affects the knees, ankles and the elbows, but we do not see it in the hips. So, if you have a single hip joint, you wanna think about emphasis related arthritis that axial arthritis, but it's large joints, not including the hips. So most serious complications of this condition, we talked about uveitis and also leg length discrepancy. A lot of times these kids actually don't have a lot of pain. Their function is not that affected. They just have this swollen knee. Um So the U V, let's talk a little bit about UBI Iis. The U V Iis associated with J I A is chronic uh non granuloma icy, which we call an interior UIs and I'll show some pictures. Um It's typically asymptomatic which is why we worry about it so much and it can precede the arthritis and the complications are serious. So, if this goes on for a long time and it's not caught and treated, it can lead to permanent vision loss, cataracts, glaucoma, glaucoma, and uh posterior sne I. So just to remind you guys, the anatomy of the eye, this pink part here is what's called the uveal tract. And then this is anterior UBI IIS. So this section here in the red box, um ciliary body iris, and then this up here in this interior chamber is where you're gonna get all that inflammation. Um and we have a picture here of what it looks like. So here's your anterior chamber cornia, Iris, sill body, everything looks nice down here. You have lots of inflammatory debris and inflammatory cells. And this is uh what you see in anterior UBI iis. This is what the ophthalmologist or optometrist is gonna see when they look at this kid in clinic. So this is a slit lamp exam. There's uh you've probably all had this at one point or another. You put your chin in a little cup, they shine the band of light in your eye. Um and you can see in here there's all these clumps of inflammatory cells. So this should be totally clear. This is an example of active U V I. So what are the complications? Will you one thing that I do always check in clinics? So I obviously, I'm not doing a slit lamp exam, but I do always try to take a look at the pupils and make sure they are around because one thing in a new patient that you can sometimes catch is these irregular pupils. So you have these adhesions that form between the iris and the lens due to that chronic inflammation. And if you see that you want to call your ophthalmologist friend right away and get that kid in the next day. Um And this is an example of posterior sneak these fibrous membranes that again form um from chronic inflammation through the pupil. Um and then leg length discrepancies. I know you all have heard a lot about already this morning. So classically, we get overgrowth around the affected knee. Um It's actually the joint that's inflamed where you, it's, it's thought that due to that increased blood flow from the inflammation, you actually get increased blood flow to the growth uh to the feces which leads to more growth. Um And if this isn't managed in the long term, it can lead to um chronic musculoskeletal issues, you can get flexion contractors, pelvic tilt leading to scoliosis. Um And so the main and for us as rheumatologists is you gotta just get that inflammation under control. And the nice thing is that if it's a young kid with a lot of linear growth left, it will typically resolve over time with catch up growth. Um You do want to get a shoe lift in there sooner than later to keep that pelvis nice and level and to prevent some of those longer term complications from developing as they, um, are evening their legs out. Um, if you have a leg length discrepancy that is not going away, that suggests that there may still be smoldering arthritis. All right. So, moving on to our next case here, this is a 14 year old female who presents with difficulty walking when she gets out of bed in the morning. She has aching and stiffness also in both of her wrists, her fingers, her knees and her feet um and has pain when she has to write at school for a long time. She's previously healthy but does have an aunt and a grandmother with rheumatoid arthritis. Um and labs are remarkable for an elevated sedimentation rate. Um A mild normal cytic anemia and a positive rheumatoid factor and that's what her hands look like. All right. So what kind of arthritis does this patient have? Who thinks it's a rheumatoid factor? Poly uh positive poly J? See if you OK. How about rheumatoid factor and negative poly J I A articular J I A systemic, see a couple for that and emphasis related arthritis. So this is rheumatoid factor, positive poly J I A and polyarticular J I A again, five or more joints and it represents about um a third to a little bit less of all of our J I A patients. There's typically symmetric involvement of both small and large joints. Um You have um often sparing of the distal interf joints, but very commonly P IP MC P and wrist involvement. Um some specific complications that we see in kids. So um T M J arthritis. So I've never heard an explanation for exactly why this is. But while we get overgrowth of the affected extremity, when we have knee arthritis, we get undergrowth of the mandible when we have T M J arthritis. And so these kids can develop pretty significant micro nathia, they get decreased oral aperture, they can have facial asymmetry. Um And so that's a a complication for us to look out for. Um We use MRI to evaluate the T M G S when needed um and try to treat this pretty aggressively. Um So R F positive Poly J I A represents about 5 to 10% of all J I A onset is typically in adolescence, although it can be earlier. And I think of this basically as early onset rheumatoid arthritis, that's how it behaves onset is usually over a few months. The arthritis is chronic and it is erosive unlike other forms of G I A that don't cause a lot of damage. Um This one can, permanent remission is pretty unlikely. So if we're lucky, we can get them off meds for periods of time, but they usually end up having to go back on. Um And as talked about earlier, they can also be C C P positive. Um Both positive R F and positive C C P. Um pretend a more severe course. Um rheumatoid factor negative poly is a little bit more common than R F positive. Um And this condition has two peak ages of onset. So either toddlerhood or school age, um onset tends to be a little more insidious than the R F positive pollies. But these kids have less joint destruction, um more likely to respond well to treatment and some of these kids will go into permanent remission, especially I find if they respond really quickly and really well to their therapy. Um U V I S is less common in our negative poly but it can be seen um less common though than an ago. Those kids are the highest risk. All right. Next case, this is a 13 year old male who presents with bilateral heel pain and limp, also complains of pain and stiffness in the right hip. Pain is worse in the morning and he's having a hard time playing soccer, which is making him very grouchy. He denies any stomach upset or weight loss um previously healthy, but does have an uncle who has really significant back problems. So on exam, he has tenderness at his achilles and planter FASA insertions on both of his feet. He has a slightly swollen left knee with pain and inflection um and limited internal rotation of the right hip. He does not have any rashes. So what type of G I A is this, take a second and decide what you think. Raise your hand if you think it's polyarticular J I A. How about emphasis related J I A nice olive articular J I A. So and undifferentiated. OK, good. You guys got this one. Emphasis related J I A. Um So this condition is characterized by arthritis and or ESIs with at least two of the following. You can have sacredly act tenderness or lumbosacra pain that positive H L A B 27 antigen, you can be a boy who's older than six. You can have acute anterior UBI iis um or a first degree relative which if with H L A B 27 associated disease and we'll talk a little about the difference between acute and chronic U V I S. So, um this is really axial and asymmetric large joint involvement that we typically see um sacred a joints, hips, knees and ankles, as well as that pain at the tendon insertion sites. Um achilles and planter fash, I'd say are the ones that we see most commonly. Um But also quads tendon tell tendon insertions. Um So more common in boys than in girls and uh more that school age and teen range, um some proportion of these kids will go on to develop I B D. So I see this in, in a solid proportion of my patients. So that's something to keep an eye out for. Is any G I symptoms or weight loss. Um The type of UBI IIS that they develop, that's associated with H L E B 27. Unlike the asymptomatic chronic interior UBI IIS, that's so hard to pick up acute interior UBI iiss. You get this angry red eye that's usually painful with photophobia. So I worry less about missing this. I send these kids to the eye doctor once a year just to get checked. But uh but not as concerned that they're gonna have a UBI Iis we're not gonna see. Um So they can have elevated inflammatory markers. Um x-rays are a little less helpful here sometimes if there's arthritis, um you can see an infusion. Um insurance will often make me get an x-ray of the sliac joints before they'll let me do an MRI but in Children, you really don't see any of those typical findings of a losing spinalis. So you don't see sali a joint fusion. You don't see bamboo spine, some of that stuff you might remember from medical school. All right. Case number four. Um So this is a six year old boy with three months of progressive difficulty climbing the stairs. His parents have to carry him out of bed in the morning and he's developed this er feminist rash on his face and on his knuckles. So, what is the diagnosis? Um who thinks this is systemic lupus erythematosus? Ok. Who thinks this is muscular dystrophy. How about celiac disease? Juvenile dermatomyositis? Good and psoriatic J I A. All right. Nice. Everybody was pretty much between lupus and J D M. This is J D M but I can see why you would think about lupus too. You're on the right track. Um, so J D M is a rare autoimmune vasculopathy affecting the muscles and the skin. Um, it's characterized by symmetric proximal muscle weakness. So, shoulder girdle, hip girdle, um kids can have elevated muscle enzymes although they don't always and um pathetic rash are almost always present and very helpful when you see them. So you have Gori's rash, which are these er plaques over the extensor surfaces of the joint. So it shows here on the hands over the MC P S P IP S and D IP S but you can see them also over the elbows and knees and then heliotrop rash is this erin rash typically above the eyelid here and on the eyelid. Um there you can actually get uh even ulcerations. I've seen them um in the here um from the vasculopathy. So, what are the findings that we see in J D M? Well, muscle weakness, um you can get the rash. Um J D M so juvenile Dermatomyositis citti where we have no weakness but just the characteristic rash, but most patients are gonna have muscle weakness. Um Gorin and heliotrope, you can see are also extremely common as are male, full capillary abnormalities. And so, um these, you can actually really get a sort of a sense of just from looking through an otoscope and you're looking um not at the cuticle but just proximal in this thin skin here at the base of the nail fold. So this is one of two places where you can see the blood vessels from the outside of the body. One of them being the retina at the back of the eye and right here um at the base of the fingernail. So normal nail fold capillaries are these nice asymmetric loops here that kind of have this like picket fence appearance. When there's abnormalities, you get dile, you get these areas of dropout and these sort of tortuous capillaries. And so um there's some pictures down here. These guys are normal, nice and straight, but then you see some giant loops dilations and then this um angiogenesis. So what happens is these um capillary loops get obstructed, you get drop out and then there's formation of new blood vessels that have this kind of tree like appearance, right? All right. So, moving on to our next case, this is a 15 year old girl who presents with limp from pain and stiffness in her ankles. She's also complaining about pain in her fingers, wrists and elbows and she's feeling just generally really tired and achy, especially first thing in the morning, she's lost £12 without trying and has chest pain with deep inspiration. Um She's also noticed that her hair is getting thinner. So on exam. She has polyarticular arthritis. She has a hard time completing a muscle, a sit up but her distal muscle strength is normal. Um, she does not have any rashes, oral ulcers or nasal ulcers. All right. So now looking at the labs, her C MP is notable for low al alumin, but she does have a normal creatine, normal muscle enzymes. She has an elevated C R P or said rate. But interestingly, her C R P is normal CBC is significant for noy anemia and a little bit of lympho penia. She has a positive antis anti R N P anti double stranded DNA and rheumatoid factor and her C three and C four complement are low. Her analysis fortunately is normal. So, what is the diagnosis is this? Who thinks this is rheumatoid factor, positive polyarticular J I A who thinks this is a malignancy. Um How about Lupe um microscopic poly ais or endo vasculitis and then post streptococcal arthritis? Good. All right, you guys got this one too. So, systemic Buma tosis. Um Lupus is an episodic multisystem autoimmune disease that causes inflammation of the blood vessels and connective tissues. Um and it is characterized by the formation of immune complexes and these anti nuclear antibodies. So, everyone who has lupus will have a positive A N A clinical manifestations are variable. Um and the natural history can be really unpredictable. So, onset of lupus in childhood is pretty common. It's somewhere between 10 and 20% of all people with lupus. Um This is a condition that as you know, is more common in girls than boys or women than men. Onset before age five is incredibly rare. And in those kids, we go looking for um genetic abnormalities of the immune system which we usually find um onset around puberty or after puberty is the most common. Um And it is a condition that is more common and more severe from people who have ancestry from populations near the equator. So, Asian African, indigenous North American and Latino ancestry um and a first degree relative uh with lupus increases your risk by about 100 fold. All right. So I think about Lubis as a process really of breakdown of immune tolerance. So you have a patient with a genetic predisposition to um developing lupus. And then there are these environmental and epigenetic factors that can lead to loss of tolerance to self antigens, development of autoantibodies. And finally, those autoantibodies go on to cause tissue damage and symptoms. And that all finally results in clinical lupus and some of these factors that we can see leading to that breakdown of self tolerance can include sunlight. So, um when patients with a predisposition, uh or patients sometimes with new onset lupus will present right after they've been to the beach for the weekend because that U V light causes breakdown of the cells in the skin and exposes those intracellular antigens to the immune system and can lead to that breakdown in self tolerance. Um, infections, as I mentioned, can be a predisposing factor. Um And there's some other factors here too. All right. So there are two second, uh two different sets of classification criteria for lupus. Um I'm gonna, the second one, I'm gonna show you I mostly included. So you'll have it in the syllabus for reference, but I like the AC R diagnostic criteria from 1997 just because they're very straightforward. Um So you have four skin, four itis and three labs. Um and you need to have four of these total of 11 criteria in order to make a diagnosis of Lubis, I've highlighted anti nuclear antibodies and immunologic disorder because really without those two things, it's not Lubis. So you got to kind of start there. They have to have an N N A and they have to have some of the characteristic antibodies associated with Lupus and then they have to have at least two of these other things. So these criteria are helpful I find to go to if you are um you know, looking at a patient and you're like this seems roomy. Could this be Lupus? I actually think it's helpful to go to the criteria and just run down this and say, have I checked these things? What do I know? Um these are the slick diagnostic criteria for Lupus which perform better but are more complex and you can refer to them in your syllabus. Um And I have just a few pictures because I need to do that as a rheumatologist. So some pictures of a classic malar rash. One important thing I'll say about a malar rash is this is a fixed aema. So if your patient comes in and says, my pa my, you know, my child gets, gets this uh malar rash, they get this really intense red cheeks and it lasts for two hours and goes away. Not a malar rash that's flushing. Um It can be raised and classically, it spares the nasal abi folds and it does not scar. In contrast, discoid rash is another really common rash and this one is scarring. So classically on the face scalp and extremities, you can get this um scaling and uh follicular plugging and you can get scarring uh here that leads to alopecia when it happens on the scalp. Um when you're examining a patient and you're thinking about lupus and you're looking at their oral pharynx, we're all very used to looking at the back, you know, at the tonsils and the posterior PHN. But you got to ask them to look up because you want to look at their hard palate, they can get these ulcerations that are actually very classic for lupus. So if you see this, this patient needs to go to the rheumatologist for sure. Um And they're often painless and the patient may not know they're there. All right. So I think we are like right on time to summarize. Um, think about rheumatic causes of limp when you have a traumatic swelling with mild to moderate pain. If it's multifocal or bilateral symptoms, if there are associated constitutional symptoms like fever and weight loss, if there's significant morning stiffness, mucocutaneous findings, or if it's just been going on for a really long time, most in useful initial labs are CBC C rate and C R P, you can get an A N A or a rheumatoid factor if you have a reason to do so, but don't use it as a screening test. Um Think about infection, postinfectious malignancy and mechanical causes of arthritis. Um And finally, your friendly rheumatologists are here to help. So you guys are always welcome to give us a call. We take um calls from the community every day. And so if you're feeling if, if you're scratching your head, um you can always feel free to give us a ring. All right. Thank you.