Systemic lupus erythematosus

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Background

  • Autoimmune disorder affecting all systems
  • Also consider drug induced lupus

Epidemiology

  • Female:Male 10:1
  • Peak in 20s-30s
  • More common in Black patients

Clinical Features

SLICC Classification Criteria 2012 [1] Requirements: >4 of the following criteria (at least 1 clinical and 1 laboratory) OR biopsy proven lupus nephritis with positive ANA or Anti-dsDNA

  • Clinical criteria
    • Malar rash, bullous lupus, photosensitivity
    • Discoid rash, hypertrophic lupus
    • Oral ulcers or nasal ulcers
    • Non-scarring alopecia
    • Synovitis
    • Serositis
    • Nephritis
    • Cerebritis, myelitis, neuropathy
    • Hemolytic anemia
    • Leukopenia or lymphopenia
    • Thrombocytopenia
  • Immunological criteria
    • ANA
    • Anti-dsDNA
    • Anti-Sm
    • Antiphospholipid antibody
    • Low complement C3, low C4
    • Direct Coombs' test in the absence of haemolytic anaemia

Organ system affected:

  • Musculoskeletal
    • Arthritis
      • Usually symmetric
      • Consider septic arthritis if there is a single inflamed joint
        • Cover for Salmonella in addition to standard coverage
  • GI
    • Lupus enteritis (mesenteric vasculitis)
      • Most common cause of acute abdominal pain
    • Pancreatitis
    • PUD
  • Dermatologic
    • Malar rash across bridge of nose
    • Discoid rash, erythematous with scale
    • Treat with topical 1% hydrocortisone
  • Renal
    • Usually a nephritis
    • Can cause a glomerulonephrosis

Differential Diagnosis

Polyarthritis

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Algorithm for Polyarticular arthralgia

Causes of Glomerulonephritis

Evaluation

Undiagnosed

  • CBC
  • Chem 10
  • Urine pregnancy
  • ANA
  • ESR
  • Urinalysis
  • Bedside echo if ill or hypotensive
  • (Consider anti-DNA, anti-Smith, anti-Nuclear, anti-phospholipid, C3,C4, direct Coombs')

Flare

  • Bedside echo if ill or hypotensive
  • CBC
  • Chem
  • Urinalysis
  • Urine pregnancy
  • As directed by organ system involved

Drug Induced Lupus

  • Anti-histone-Ab positive 95% of the time
  • Make sure to review medications
    • High risk:
      • Procainamide (antiarrhythmic)
      • Hydralazine (antihypertensive)
    • Moderate to low risk:
      • Infliximab anti (TNF-α)
      • Etanercept anti (TNF-α)
      • Isoniazid (antibiotic)
      • Minocycline (antibiotic)
      • Pyrazinamide (antibiotic)
      • Quinidine (antiarrhythmic)
      • D-Penicillamine (anti-inflammatory)
      • Carbamazepine (anticonvulsant)
      • Oxcarbazepine (anticonvulsant)
      • Phenytoin (anticonvulsant)
      • Propafenone (antiarrhythmic)
      • Chlorpromazine (antipsychotic)

Fever in SLE

  • Must differentiate disease activity (flare) from infection

Risk Factors for Infection [2]

  • Neutropenia/Lymphopenia
  • Hypocomplementemia
  • Immunosuppressive therapy (especially Azathioprine [3])

Studies

  • CRP: sensitivity 100%, specificity 90% >1.35mg/dL [4]
  • PCT: sensitivity 75%, specificity 75% [5]

Management

  • Inflammatory complications
    • Methylprednisolone 1-2mg/kg in most cases
  • Infectious
    • Stress dose steroids with hydrocortisone 100mg IV Q8hr if on or recently on steroids
  • Dermatologic
    • Hydrocortisone 1% cream
  • If drug induced lupus, stop medication and consider alternative

Disposition

  • Suspected new diagnosis can have out patient workup if well appearing
  • Mild flairs can have expedited out patient management
  • Musculoskeletal symptoms can usually be managed as out patients
  • Chest pain requires urgent ACS evaluation
  • Infections usually require admission for antibiotics and systemic corticosteroids

See Also

References

  1. Lisnevskaia L, et al. Systemic Lupus Erythematosus. Lancet. 2014 May 29. Epub ahead of print.
  2. Cuchacovich, R., & Gedalia, A. (2009). Pathophysiology and clinical spectrum of infections in systemic lupus erythematosus. Rheumatic diseases clinics of North America, 35(1), 75–93. doi:10.1016/j.rdc.2009.03.003
  3. Zhou, W. J., & Yang, C.-D. (2009). The causes and clinical significance of fever in systemic lupus erythematosus: a retrospective study of 487 hospitalised patients. Lupus, 18(9), 807–812. doi:10.1177/0961203309103870
  4. Kim, H.-A., Jeon, J.-Y., An, J.-M., Koh, B.-R., & Suh, C.-H. (2012). C-reactive protein is a more sensitive and specific marker for diagnosing bacterial infections in systemic lupus erythematosus compared to S100A8/A9 and procalcitonin. The Journal of rheumatology, 39(4), 728–734. doi:10.3899/jrheum.111044
  5. Scirè, C. A., Cavagna, L., Perotti, C., Bruschi, E., Caporali, R., & Montecucco, C. (2006). Diagnostic value of procalcitonin measurement in febrile patients with systemic autoimmune diseases. Clinical and experimental rheumatology, 24(2), 123–128.