Rheum vs. ID I

Over this past month, we've had two puzzling patients whose diagnoses are not transparent. In both cases, rheumatology and infectious disease have been entirely flummoxed and each consult service insists it's a disease of the other. These professional disagreements are not only interesting but also reflect the uncertainty in medicine. The next few posts will all be related.

A 50 year old woman presents with several days of severe neck pain, bilateral knee pain, and left ankle pain. She has had "arthritis" for many years in the past but has never seen a doctor; the flares of this "arthritis" affect her neck and knees but resolve spontaneously. It's never been this bad before. Several days prior to admission while on a trip to Peru, she began having severe headache, neck pain, and joint swelling. She cannot easily move her neck. Her knees both have decreased range of motion to the point that she cannot walk. She denies fevers, chills, night sweats, photophobia, cough, dyspnea, chest pain, nausea, vomiting, diarrhea, or dysuria.

Her past medical history is only significant for joint aches and gastritis. She takes ibuprofen as needed. She has no allergies. There is a family history of "arthritis." She grew up in Peru where she worked in villages. She denies drinking, smoking, and drugs. She recently traveled to Peru but was mostly in large cities. She has no sick contacts. She did drink unpasteurized milk. She has had no odd animal exposures.

On admission, she was afebrile, and her vital signs were stable. She was ill-appearing and refused to move or interact. Her neck had decreased range of motion, limited by pain. She did not have focal neurologic deficits. She had a 2/6 systolic ejection murmur best heard at the upper sternal border. Her bilateral knees were swollen and warm but not erythematous. Her left ankle had a mild effusion. The rest of her exam was unremarkable. Her basic labs were all normal, including her WBC count.

Strangely to me, she was admitted to orthopedics. They tapped her right knee and found 130,000 white blood cells, a sky high number concerning for infection, neutrophil predominant, no crystals. The gram stain and subsequent culture were negative. The left knee was tapped, 90,000 white blood cells, neutrophil predominant, no crystals, negative gram stain and culture. She was started on vancomycin to cover Staphylococcus and Streptococcus as well as cefazolin; I'm not sure what that was covering. Orthopedics then pan-consulted neurology to rule out meningitis, ID to treat the presumed septic joint, and rheumatology for kicks.