Poncet's Disease or Tubercular Rheumatism

• Poncet's Disease or Tuberculous rheumatism is poly arthritis with visceral tuberculosis but no bacteriological evidence of joint involvement.
• The first detailed description of the disease was given by Antonin Poncet in 1897
• It is different from tuberculous arthritis, which is usually monoarticular and is caused by direct tuberculous infection. Poncet's disease remains a diagnosis of exclusion.
• There are isolated reports of this disease entity from India and abroad. 
• The clinical presentation may be primary tuberculosis as the first manifestation or secondary to chest tuberculosis. The pattern of articular involvement is predominantly non-migratory, polyarticular with mild to moderate functional incapacity. Morning stiffness is usually absent. 
• Response to anti-tubercular treatment with no residual deformity is usually seen.
• Sterile polyarthritis can some times complicate tuberculosis.
• Various mechanisms like 

1. hypersensitivity response to tuberculous protein, 
2. Increased PPD induced reactivity of synovial fluid lymphocytes compared with that of peripheral blood lymphocyte,
3. Antigenic similarity between a fraction of tubercle bacilli and human cartilage and circulating immune complexes against synovium have been postulated. 
4. Presently a cell - mediated cross reactive immune response to Mycobacterium tuberculosis is thought to be the cause of this reactive inflammatory arthropathy of Poncet's disease.