We discussed a middle aged man who presented with acute painful knee with daily fevers, leukocytosis, elevated inflammatory markers (ESR, CRP, Ferritin) and transaminitis found to have adult onset still’s disease. Our patient had a debridement in the OR due to concerns of septic arthritis however no pus was seen and joint fluid aspiration showed inflammation (not infection). Due to daily fevers in the hospital and leukocytosis, rheumatology was consulted and found a ferritin >17k. Patient met Yamaguchi criteria (see below) and was diagnosed with Still’s Disease. Patient was started on high dose steroids and his fever, transaminitis, arthritis improved. 

Still’s Disease Yamaguchi criteria

• Major
  1. Fever>39, >1 week (patient met this)
  2. Arthritis >2 weeks (possible?)
  3. Rash (our patient had rash after starting abx) – not characteristic rash seen in stills 
  4. Leukocytosis (patient met this)
• Minor
  1. Sore throat (patient does not have)
  2. LAD (does not have)
  3. Hepatomegaly, Splenomegaly (patient does not have)
  4. High AST/ALT/AlkPhos (has this)
  5. Negative ANA and RF (has this)

Ddx for painful joints

• Infections
  1. Disseminated gonorrhea (mono or oligoarticular)
  2. S. Aureus (monoarticular)
  3. Strep Pneumoniae
  4. Beta hemolytic strep
  5. Fungi like candida, cocci, blaso, cryptoneoformans
  6. TB (pott’s disease)
  7. Other (Nocardia, Brucella)
  8. Syphilis and Chlamydia
• Inflammation
  1. Spondyloarthritis (Reactive arthritis, Ankylosing Spondylitis, Psoriatic Arthritis)
  2. Lofgrens Syndrome (Sarcoid)
  3. HSP
  4. Cryoglobulin – oligoarticular, HCV, purpura 
  5. RA
  6. SLE
  7. Still’s Disease
  8. DM/PM
• Crystals
  1. Gout (monosodium urate crystals)- oligo/polyarticular
  2. Pseudogout (CPPD) – oligo/polyarticular
• Tumor
  1. Chondroma, Giant cell tumor, osteoma
• Blood
  1. Clotting disorder
  2. Trauma