J: joint, bones, skin


The final systems are the extremities, Here are a few mnemonics for the approach to ARTHRITIS, ORTHOPEDICS and DERMATOLOGYZ




  • Aureus and gonorrhea: septic artritis
  • Rifringent crystals: gout and pseudogout
  • Trauma
  • Hemarthrosis


  • Rheumatic fever
  • Infection: bacterial (gonorrhea) or post-infectious (reactive arthritis after GI/GU)
  • Tic: Lyme
  • Infection viral: hepatitis, HIV, parvovirus
  • SLE



For orthopaedics it’s easy to develop a habit of looking at the Xray first and assuming there are no injuries if it’s normal. This is a recipe for error–and indeed missed fractures are among the most common errors in emergency medicine. My mnemonic ORTHOPEDIC  starts with injuries not requiring xrays (or missed by premature focus on xrays), then considers xray findings or lack of findings, and then considers follow up imaging or immobilization:


  • Open fracture
  • Reduce dislocation
  • Test neurovascular, consider occult injury (eg knee dislocation) and delayed injury (eg compartment syndrome from forearm fracture)
  • Hand: remove ring, test for scisoring
  • Other injuries: tendon/ligament, eg Achilles tear in ankle injury, quad/patellar tear in knee injury, UCL tear in thumb injury


  • Proper bones and views, eg consider hip pain referred to knee; scaphoid/patellar/carpal tunnel views
  • Extensive injury, eg if you see one fracture look for multiple fractures, fracture-dislocations (eg Galeazzi, Monteggia, Essex-Lopresti)
  • Diseased bone, eg fracture out of proportion to mechanism consider pathological fracture
  • Invisible: the “Silent S” fractures, eg SCIWORA, Scapholunate, Sacroiliact, Shenton’s line (femur), Salter-Harris, Stirrup (Lisfranc)

Follow up for occult fractures

  • Cast and refer, eg scaphoid fracture
  • Scan to r/o fracture, eg CT scan for hip fracture, bone scan for stress fracture



Most rashes we see in the ER are not dangerous and can be followed by the GP or referred to derm. But there are rashes we shouldn’t miss in the ER. There are a few approaches you can use. The modified Lynch algorithm is the most thorough, using the rash classification


  1. Erythema
    1. fever
      1. Nikolski positive: SSS, TEN
      2. NIkolski neg: scarlet, cellulitis/nec fasc, Kawasaki, TSS
    2. afebrile
      1. Nikolski positive: TEN
      2. Nikolski negative: anaphylaxis, scromboid
  2. Petechial
    1. fever
      1. palpable: meningitis, endocarditis, HSP, gono
      2. non-palpable: DIC, TTP
    2. afebrile
      1. palpable: vasculitis
      2. ITP
  3. Maculo-papular
    1. fever
      1. central: DRESS, viral, Lyme
      2. peripheral: meningitis, RMSF, EM/SJS
    2. afebrile
      1. central: drug
      2. peripheral: eczema, psoriasis, scabies


  1. Vesico-bullous
    1. fever
      1. diffuse: varicella, smallpox, DIC, gono
      2. local: nec fasc, hand-foot-mouth
    2. afebile
      1. diffuse: bullous pemphigoid, pemphigoid vulgaris, drug-induced bulous
      2. local: contact derm, zoster, burn, dyshidrotic eczema
  2. Pustular
    1. febrile: AGEP
    2. afebrile: folliculitis


I’ve put these into a mnemonic to provide another approach, starting with drug history and then thinking of the head-to-toe exam: Think of DERMATOLOGYZ

  • Drug-related ABCDS: Anaphylaxis, AGEP, Bullous drug-induced, Captopril angioedema, DRESS, Stevens-Johnson
  • Eye conjunctivitis: Kawasaki
  • Rigid neck: meningitis
  • Murmur: endocarditis
  • Abdomen: splenomegaly from mono
  • Toxic shock: STSS, SSS
  • Out of proportion: necrotizing fasciitis
  • Low platelet: TPP, ITP, vasculitis, DIC
  • Oedema: HSP
  • Gono/syphilis
  • lYme
  • Zoster


An alternative method is to use my system-based approach:

  • Airway: anaphylaxis, SJS, Kawasaki, Mono
  • B
  • Cardio: endocarditis, nec fasc, toxic shock
  • D neuro: meningitis, Lyme
  • E
  • Fertility: gono, syphilis
  • G
  • Heme: ITP TTP, DIC, HSP
  • I tox: AGEP, bullous drg-induced, captopril angioedema, DRESS, SJS
  • J regular derm: eczema, contact deem, etc

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s