Rheum vs. ID III

A 25 year old woman presents with a four year history of right ankle ache. About eight months ago, the ankle pain acutely worsened to the point that she could not bear weight on it. She presented to the doctor and an ankle tap showed a WBC count of 20,000, no organisms on Gram stain or culture, and AFB negative. She then proceeded to get a synovial biopsy which showed acute synovitis, not characteristic of rheumatoid arthritis. Nothing was really done at the time and she was sent back to jail where she had been. Several months later, the ankle was still bothering her so rheumatology admitted her for a midfoot deep tissue biopsy and expedited work-up. The other pertinent history is that over the last 8 months, she converted her PPD. Rheumatology then consulted infectious disease for a question of TB arthritis.

Her past medical history, medications, allergies, and family history are non-contributory. She denies drinking, smokes a few cigarettes a day, and has a history of IV drug use. She injects heroin, last use several months ago, but she denies injecting into her ankle. She denies fever, chills, appetite change, weight loss, cough, hemoptysis, chest pain, dyspnea, nausea, vomiting, diarrhea, dysuria, edema, photosensitivity, or rash. She did say she had night sweats.

She was afebrile and her vital signs were stable. Her exam was completely benign except for her ankle which was swollen, tender, and with decreased range of motion (limited by pain). Initial cultures of her deep foot biopsy are negative for all organisms. Her chest X-ray is clear. Labs were significant for a strongly positive ANA (>1:640) and a mildly elevated rheumatoid factor.

The rheum-ID conflict came up over TB arthritis. 90% of TB in immunocompetent patients is pulmonary, and of the extra-pulmonary manifestations, arthritis is uncommon. Furthermore, TB arthritis favors large joints like the hip and knee rather than the ankle. Despite her PPD change, she has nothing going for TB except the vague night sweats. Of course, TB can do anything, but we decided that she did not need RIPE treatment (the regimen for active tuberculosis) until the culture results of the deep tissue biopsy came back.

Nevertheless, rheumatology as the primary team decided to start RIPE. They sent her to TB clinic who wanted to rule her out for pulmonary TB despite lack of pulmonary symptoms and a clear chest X-ray. This was another example of case that was not completely clear cut between specialist services. It was nice, though, for me to review rheumatology as I may not get to do that elective this year.