reactive arthritis (Reiter's syndrome)

introduction

reactive arthritis refers to an acute inflammatory aseptic arthritis complicating an infection elsewhere in the body.
60-85% of patients are HLA-B27 positive
Reiter's syndrome was a term used to describe a subset of these patients who developed:
- reactive arthritis
- nonspecific urethritis
- and conjunctivitis, often accompanied by iritis
the main bacteria implicated, and the two main sources of the precipitant infection:
- enteric infections
  - Shigella flexneri
  - several Salmonella species
  - Yersinia enterocolitica
  - Campylobacter jejuni
  - Clostridium difficile
- sexually transmitted infections
  - Chlamydia trachomatis
  - Chlamydia pneumoniae
  - Ureaplasma urealyticum

usually begins with urethritis or diarrhoeal episode followed by conjunctivitis and then the reactive arthritis
arthritis begins within 1 month of infection in 80% of patients.
- it is usually acute, asymmetric, and oligoarticular and predominantly involves the joints of the lower extremities (eg, knees, ankles, feet, wrists).
- dactylitis or sausage digit is a diffuse swelling of a solitary finger or toe and is a distinct feature of both reactive arthritis and psoriatic arthritis.
- plantar fasciitis and Achilles tendonitis also are common.
- up to 70% develop sacroiliitis

Rx underlying infection if needed
non-steroidal anti-inflammatory drugs (NSAIDs)
consider local corticosteroids for uveitis, persistent monoarthritis, fasciitis, and tendonitis.

Systemic corticosteroids should be avoided because they can aggravate the cutaneous manifestations of the disease.