A case of progressive pseudorheumatoid arthropathy of 'childhood' with the diagnosis delayed to the fifth decade.

Progressive pseudorheumatoid arthropathy of childhood (PPAC) is a rare single gene disorder which is frequently misdiagnosed as juvenile rheumatoid arthritis. It is characterised with arthralgia, joint contractures, bony swelling of metacarpophalangeal and interphalangeal joints and platyspondyly. Clinical and laboratory signs of joint inflammation such as synovitis, a high erythrocyte sedimentation rate and an elevated C-reactive protein level are usually absent. Although the disease begins early in life (usually between 3 and 8 years of age), the diagnosis may be delayed. In the present case report, we describe a male patient diagnosed with PPAC at the age of 46 years, although he had been exhibiting the typical radiological and clinical features of the disease since the age of 7 years.