Micah Mooberry ACC Conference 1/16/2008

Transcription

1 Acute Monoarticular Arthritis Micah Mooberry ACC Conference 1/16/2008

2 CASES Case #1: 48 yo WF h/o RA treated with long term, low dose Prednisone. Presents with 2 day h/o red, swollen, painful L knee. No prior h/o knee involvement. No recent trauma or surgery. No illicit drug use or risky sexual behaviors reported. - PE: Afebrile, swollen/erythematous L knee with effusion - Studies: WBC 11, ESR 55; * synovial fluid Gram stain neg, WBC 48, culture pending

3 CASES Case #2 81 yo WM h/o diet controlled DM, HTN, reported h/o gout. 2 day h/o R ankle pain, swelling and difficulty walking. - PE: T 38.2; erythema and swelling of dorsal aspect of midfoot and ankle; tender to palpation

4 So, now what?!?! Can you chalk both cases up to acute flares of RA and gout, respectively? How good are clinical signs and symptoms at predicting the diagnosis of septic arthritis? How good are laboratory data at predicting the diagnosis of septic arthritis? Do I have to tap the joint?

5 But first A quick review of Acute Polyarthritis Polyarticular Arthritis Typically inflammation of 4 or more joints Symptoms lasting < 6 weeks Often infectious in nature, or just early detected rheumatic disease Evaluation Hepatitis B/C, Parvovirus titers,? Borrelia CBC, LFTs? Close monitoring

6 Viruses that cause arthalgias Commonly seen Hepatitis B and C Rubella and vaccine Parvovirus Alphaviruses Occasionally seen Epstein Barr virus Human immunodeficiency virus Mumps Hepatitis A Coxsackie virus Echovirus Adenovirus Varicella-zoster Herpes simplex Cytomegalovirus 2008U UpToDate t

7 Chronic Polyarthritis Symptoms > 6 weeks Differential: RA; Still s disease SLE Seronegative spondyloarthropathies (psoriatic, AS, Reiter s s, IBD, etc.) Inflammatory OA Other connective tissue diseases (Sjogren s, polymyositis, dermatomyositis, scleroderma, MCT disease) Polyarticular crystal-induced synovitis (rare)

8 Evaluation 2008 UpToDate

9 Major causes of inflammatory polyarticular rheumatism Infectious arthritis Crystal-induced arthritis Bacterial Lyme disease Bacterial endocarditis Viral Other infections Systemic rheumatic illnesses Systemic lupus erythematosus Systemic vasculitis Systemic sclerosis Postinfectious (reactive) arthritis Rheumatic fever Polymyositis/dermatomyositis Still's disease Reactive arthritis Behcet syndrome Enteric infection Relapsing polychondritis Other seronegative spondyloarthritides Ankylosing spondylitis Psoriatic arthritis Inflammatory bowel disease Other systemic illnesses Sarcoidosis Palindromic rheumatism Familial Mediterranean fever Rheumatoid arthritis Inflammatory osteoarthritis Malignancy Hyperlipoproteinemias 2008 UpToDate

10 Common Patterns Symmetric: RA, SLE, Scleroderma Association w/ dactylitis: Psoriatic, AS, Reiter s Association w/ SI: IBD, AS, Psoriatic Affects DIP: OA (Heberden s nodes), Psoriatic Affects PIP: RA, SLE, Scleroderma, OA (Bouchard s nodes) Affects MCP: RA, SLE, Scleroderma, Hemochromatosis

11 Now. back to Monoarticular Arthritis Box 1. Differential Diagnosis for Acute Monoarthritis* Infection (bacterial, fungal, mycobacterial, viral, spirochete) Rheumatoid arthritis Gout Pseudogout Apatite-related t arthropathy Reactive arthritis Systemic lupus erythematosus Lyme arthritis Sickle cell disease Dialysis-related amyloidosis Transient synovitis of the hip Plant thorn synovitis Metastatic carcinoma Pigmented villonodular synovitis Hemarthrosis Neuropathic arthropathy Osteoarthritis Intra-articular injury (fracture, meniscal tear, osteonecrosis) *Adapted from Klippel et al.18

12 Monoarticular Arthritis The BIG 3: Crystalline disease Infection Trauma Crystalline disease Gout: monosodium urate crystals; negatively birefringent; podagra Pseudogout: calcium pyrophosphate; positively birefringent; knee is most common joint

13 Infectious Arthritis Gonococcal Non-gonococcal bacterial Fungal (sporotrichosis most common) Mycobacterial (immunocompromised) Lyme disease Viral

14 Gonococcal Arthritis Most common cause of bacterial arthritis in young adults 2-3 x more common in women Two syndromes Tenosynovitis, vesiculopustular skin lesions, polyarthralgias without purulent arthritis Purulent arthritis without skin findings Gram stain positive in < 25% Synovial cultures often negative If high suspicion, culture urethra, cervix, rectum & pharynx for Neisseria

15 Non-gonococcal bacterial arthritis Typically affects large joints Staphylococcus and Streptococcus are most common causes (approx. 70% of cases) Most potentially dangerous and destructive form of acute monoarthritis (esp. Staph) Mortality rate of 7-15% for in-hospital settings S. epidermidis common with prosthetic joints Encapsulated organisms in patients with splenectomy

16 Routes of bacterial invasion

17 Back to the problem at hand How good are clinical signs and symptoms at predicting the diagnosis of septic arthritis? How good are laboratory data at predicting the diagnosis of septic arthritis? Do I have to tap the joint? Septic arthritis often difficult to distinguish from an acute flare of a chronic arthritis (gout, RA, etc.), as the symptoms overlap

18 Generally Accepted Guidelines Categories of synovial fluid based upon clinical and laboratory findings Measure Normal Noninflammatory Inflammatory Septic Hemorrhagic Volume, ml (knee) <3.5 Often >3.5 Often >3.5 Often >3.5 Usually >3.5 Clarity Transparent Transparent Translucent-opaque Opaque Bloody Color Clear Yellow Yellow to opalescent Yellow to green Red Viscosity High High Low Variable Variable WBC, per mm3 < ,000 2,000-10,000 >100,000* 200-2,000 PMNs, percent <25 < Culture Negative Negative Negative Often positive Negative Total protein, g/dl LDH (compared to levels in blood) Very low Very low High Variable Similar Glucose, mg/dl Nearly equal to blood Nearly equal to blood >25, lower than blood <25, much lower than blood Nearly equal to blood 2008 UpToDate

19 Generally Accepted Guidelines

20 Does This Adult Have Septic Arthritis? JAMA, April 4, 2007 Vol. 297, No. 13, Review of the literature from 1966 through January 2007 Included studies that contained original data on the accuracy or precision of historical items, PE, serum or synovial fluid data for diagnosing i septic arthritis Primary outcome measures were LRs for all signs/symptoms and lab data used to distinguish septic arthritis from other causes of acute arthritis

21 Reason for Exclusion of Studies Margaretten, M. E. et al. JAMA 2007;297: Copyright restrictions may apply.

22 Study Info continued Included patients from Rheum clinics, ED and hospitalized patients 2 prospective p studies showed pre-test probability/prevalence of septic arthritis in acutely swollen, painful joints to be 8% & 27% respectively Limitations: Different standards for dx of septic arthritis No substratification of population subsets Only 3 studies included gonococcal arthritis

23 Results Risk factors: Likelihood of septic arthritis increases with: Age > 80 DM RA Recent joint surgery Hip or knee prosthesis Skin infection Skin infection combined with joint prosthesis

24 More Results Signs: Fever had poor predictive value Sens 46%, Spec 31% LR+ 0.67, LR- 1.7 Serum labs: WBC, ESR and CRP all had limited diagnostic power to change pre-test probability Poor specificities

25 And Still More Results Synovial fluid analysis Progressively higher synovial WBC counts increase the likelihood of septic arthritis WBC < 25K; LR WBC > 25K; LR+ 2.9 WBC > 50K; LR+ 7.7 WBC > 100K; LR Additionally, PMN percentage > 90% also increases likelihood of septic arthritis (LR+ 3.4)

26 Likelihood Ratios for Risk Factors, Signs, and Serum Laboratory ato Values Margaretten, M. E. et al. JAMA 2007;297: Copyright restrictions may apply.

27 Sensitivity of Symptoms and Signs* Margaretten, M. E. et al. JAMA 2007;297: Copyright restrictions may apply.

28 Test Characteristics of Synovial Fluid Studies Margaretten, M. E. et al. JAMA 2007;297: Copyright restrictions may apply.

29 Other Synovial Fluid Laboratory Test Results Margaretten, M. E. et al. JAMA 2007;297: Copyright restrictions may apply.

30 SUMMARY Clinical symptoms and PE signs, such as fever, are poor predictors of septic arthritis Certain risk factors increase the likelihood of septic arthritis (DM, RA, etc.), and if present should prompt careful consideration of tapping joint Serum labs are poor predictors of septic arthritis Synovial WBC > , with PMN > 90%, significantly increase likelihood of septic arthritis If in doubt, obtaining synovial fluid is the best and only reliable way to accurately make the diagnosis

31 So, what about our cases? Case #1: 48 yo WF h/o RA treated with long term, low dose Prednisone. Presents with 2 day h/o red, swollen, painful L knee. No prior h/o knee involvement. No recent trauma or surgery. No illicit drug use or risky sexual behaviors reported. - PE: Afebrile, swollen/erythematous L knee with effusion - Studies: WBC 11, ESR 55; * synovial fluid Gram stain neg, WBC 48, culture pending

32 So, what about our cases? Case #2 81 yo WM h/o diet controlled DM, HTN, reported h/o gout. 2 day h/o R ankle pain, swelling and difficulty walking. - PE: T 38.2; erythema and swelling of dorsal aspect of midfoot and ankle; tender to palpation

33 So, what about our cases? Case #1 If you start with pre-test probability of 18% for septic arthritis.. Risk factor of RA (LR+ 2.5) increases prob. to 38% Synovial WBC 48 (LR+ 2.9) increases prob. to 64% Adding PMN count could provide additional data Would likely empirically treat while waiting on culture results

34 So, what about our cases? Case #2 Risk factor of age > 80 (LR+ 3.5) and DM (LR+ 2.7) increase probability from 18% to 40% No prior confirmed h/o gout by synovial fluid analysis Fever and other clinical symptoms are not helpful in determining presence of infection; however gout much more common disease Patient would likely benefit from joint tap to help provide more useful data to guide management

35 References Does This Adult Patient Have Septic Arthritis? JAMA, April 4, 2007 Vol. 297, No. 13; Monoarthritis: Differential Diagnosis. Am J Med. 1997; 102 (suppl 1A): 30S-34S. Septic arthritis in patients with pre-existing existing inflammatory arthritis. CMAJ, May 22, 2007; 176 (11); Rheumatology:5. Diagnosis and management of inflammatory polyarthritis. CMAJ, June 27, 2000; 162 (13); Evaluation ation of the adult with monoarticular pain. Helfgott, Simon M. Uptodate.com. Evaluation of the adult with polyarticular pain. Pinals, Robert S. Uptodate.com. Does the presence of crystal arthritis rule out septic arthritis? The Journal of Emergency Medicine, Vol. 32, No. 1, pp , 2007.