Systemic lupus erythematosus

Revision as of 23:07, 28 June 2014 by Ostermayer (talk | contribs) (Differential Diagnosis)

Background

  • Autoimmune disorder affecting all systems

Epidemiology

  • Female:Male 10:1
  • Peak in 20s-30s
  • More common in African Americans


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

Workup

Undiagnosed

  • CBC
  • Chem 10
  • Urine pregnancy
  • ANA
  • ESR
  • UA
  • 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
  • UA
  • Urine pregnancy
  • As directed by organ system involved

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

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

Sources

  • Rosen's
  • Up to date
  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.