6/20/16 ZSFG pearls – GGOs and purpura

Thank you to Kenny Petterson for finishing intern year STRONG with an amazing morning report case. He presented a 45 y/o man with diabetes who presented with multisystem organ failure and a petechial rash.

Ground glass opacities

Ddx of ground glass opacities in the lung

  •          Water (pulmonary edema)
  •          Pus (infection, inflammation)
  •          Blood (diffuse alveolar hemorrhage)


Now lets talk purpura.

This is an opportunity to highlight some amazing resources from the UCSF dermatology department: the dermatology glossary and the purpura/petechiae online module. Go to the dermatology glossary to demystify specific skin terms. The online modules give you a case-based deep dive into specific dermatologic disorders.

Purpura are defined as red-purple skin lesions that result from blood extravasation into tissue. They are non-blanching. Morphologically they are divided into


  •    A sign of vascular inflammation or damage, usually a small or medium vessel vasculitis
  • Palpable purpura is the hallmark of a leukocytoclastic vasculitis, but LCV is a histopathologic diagnosis
  •    Ddx
    •        Primary rheum
      • ANCA-associated
      •  Cryoglobuinemic vasculitis
      • Polyarteritis nodosa
      • Henoch-schonlein purpura (rare in adults)
      •      Urticarial vasculitiS
      •  SLE
  •   Infection
    •          HBV-associated PAN
    •          HCV associated cryoglobulinemia
    •          Purpura fulminans associated with DIC
  •   Malignancy-related
  •   Medication effect (meds can cause an LCV on their own!)
Lindy Fox’s recommendation for first line w/u of palpable purpura
  •          CBC w platelets
  •          ESR/CRP
  •          ANA
  •          ANCAs
  •          Complements
  •          UA
  •          Infectious w/u including HIV, HCV, HBV, +/- ASo or strep throat culture and cryos
Non-palpable or macular purpura
  • Usually noninflammatory
  • further subdivided by size

Petechiae <3mm in size

  •   Ddx
    •          Qualitative and quantitative platelet disorders
    •          DIC and infection (mycoplasma was a strong consideration in our case today)
    •          Increased intravascular venous pressure (due to clot or obstruction)
    •          Inflammatory skin disease
    •          Increased vascular fragility including d/t vitamin deficinecies like scurvy

  Ecchymosis >5mm in size

  •   External trauma
  •   DIC and infection
  •   Coagulopathy
  •   Skin weakness/fragility
  •   Waldenstrom’s



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