Reactive arthritis

• What is reactive arthritis?
• Statistics on reactive arthritis
• Risk factors for reactive arthritis
• Progression of reactive arthritis
• Symptoms of reactive arthritis
• Clinical examination of reactive arthritis
• How is reactive arthritis diagnosed?
• Prognosis of reactive arthritis
• How is reactive arthritis treated?
• References

What is reactive arthritis?

Reactive arthritis (formerly known as Reiter’s syndrome) is an inflammatory arthritis following an infection in which no viable microorgansim is found in the synovial fluid of joints.

Statistics on reactive arthritis

Believed to be the most common form of acute arthritis in the young adult population. The true incidence is not known but studies have shown that 1-3% of individuals infected during an epidemic of bacterial diarrhoea may develop reactive arthritis. There is a strong male prevalence in venereal onset reactive arthritis.

Risk factors for reactive arthritis

The cause is believed to be a microbial agent that triggers the disease in a genetically susceptible individual. Common gastrointestinal organisms include Shigella, Salmonella, Yersina and Campylobacter and the genitourinary pathogen Chlamydia Trachomatis.

Progression of reactive arthritis

Treatment has generally helped the symptoms of the conditon without affecting the natural history.

• Almost 60% of patients have chronic relapses of peripheral arthritis when followed over a longer period and nearly 35% become disabled in some way;
• 50% have back pain and evidence of sacroidiitis. The flares may recur spontaneously or follow a repeated genitourinary infection or bout of diarrhoea;
• No clinical features are especially helpful in establishing a prognosis;
• Those with HLA B27 are more likley to have back pain but not necessarily more frequent or severe relapses.

How is reactive arthritis diagnosed?

• Urinalysis – sedimentation rate often raised;
• Full blood count – white cell count often raised.

If indicated:

• Urethral swabs/first void urine in men or high vaginal and endocervical swabs in women – for PCR for Chlamydia trachomatis;
• Stool sample – only if there is a disabling gastrointestinal upset.

Prognosis of reactive arthritis

The majority of patients have symptoms lasting from weeks to months. Up to 50% of patients may have repeated episodes of arthritis, and 15-30% of patients may have long term arthritis.

How is reactive arthritis treated?

• Rest and physical therapy;
• Pharmacotherapy – non-steroidal anti-inflammatory drugs – used to manage acute and chronic flares;
• Conjunctivitis does not require treatment. Treating the chlamydial urethral infection may shorten the course of the arthritis. Treatment consists of azithromycin (or a tetracycline);
• Corticosteroids – intra-articular injection to treat 1-3 resistant joints or managing plantar fasciitis or Achilles tendinitis. Only rarely will large oral doses be be needed (40-80 mg).
• Immunosuppressants (methotrexate, azathioprine) – used for the small subgroup who have progressive disease unresponsive to the above measures.

References

1. Braunwald, Fauci, Kasper, Hauser, Longo, Jameson. Harrison’s Principles of Internal Medicine. 15th Edition. McGraw-Hill. 2001
2. Cotran, Kumar, Collins 6th edition. Robbins Pathologic Basis of Disease. WB Saunders Company. 1999.
3. Haslet C, Chiliers ER, Boon NA, Colledge NR. Principles and Practice of Medicine. Churchill Livingstone 2002.
4. Hurst JW (Editor-in-chief). Medicine for the practicing physician. 4th edition Appleton and Lange 1996
5. Kumar P, Clark M. CLINICAL MEDICINE. WB Saunders 2002 Pg 427-430. Longmore M, Wilkinson I, Torok E. OXFORD HANDBOOK OF CLINICAL MEDICINE. Oxford Universtiy Press. 2001
6. McLatchie G and LEaper DJ (editors). Oxford Handbook of Clinical Surgery 2nd Edition. Oxford University Press 2002.
7. Raftery AT Churchill’s pocketbook of Surgery. Churchill Livingsone 2001.