18th January 2024

Reactive arthritis 

Reactive arthritis often presents as a monoarthritis or oligoarthritis of the large joints. RA may occasionally present similarly, particularly in the knee, where the physical signs can be identical. There are, however, some findings that are more suggestive of reactive arthritis than RA. These include :

• History of recent urethritis or enteric infection
• Asymmetric pattern of joint involvement, particularly in the hands
• Involvement of not only the joint but also the tenosynovium, entheses, and surrounding tissues. This can manifest as the characteristic “sausage” swelling in the digits of the hands and feet.
• Keratoderma blennorrhagica or circinate balanitis
• Radiological evidence of sacroiliitis and/or spondylitis
• Presence of HLA B27