Late post from last week. Thanks to our excellent sub-I Juan Spinnato for presenting the case of an older man with subacute cough, dyspnea and polyarthralgias who was found to have a marked eosinophilia, and was ultimately diagnosed with a large intrahepatic mass, now favored to be cholangiocarcinoma 😦


  • Polyarthralgias have a huge differential, so certain features can help narrow your differential
    • Distribution: pattern (small vs large joints), symmetry, axial involvement
    • Extra-articular manifestations (rash, eye symptoms, muscle weakness)
    • Duration: <6 weeks is often viral, >6 weeks bears further investigation for other causes
    • Periodicity: intermittent (crystalline arthritis) vs constant
    • Demographics (gender, age, race, family hx)


We also talked about the utility of inflammatory markers!

Key points

  • What can increase or decrease the ESR?
    • Increase: infection, inflammation (duh), malignancy, trauma
    • Decrease: abnormally shaped RBCs (SCD, spherocytosis, etc), heart failure, extreme leukocytosis
  • There are underlying conditions that can ‘falsely‘ elevate the ESR more than expected
    • Elevate: older age (correction formula: ULN of reference range = age/2 for men and (age + 10)/2 for women), female gender, ESRD, obesity
  • Conditions that can cause a discrepancy between ESR and CRP
    • Elevated ESR, normal CRP
      • monoclonal immunoglobulins
      • SLE (felt to be because type I IFNs produced in SLE inhibit CRP synthesis by liver)
        • Elevated CRP in SLE should raise suspicion for underlying bacterial infection


Richie et al. Diagnostic Approach to Polyarticular Joint Pain. Am Fam Phys. 2003.