Reactive Arthritis

Key Facts

Sterile inflammation of the synovial membrane, tendons and fascia triggered by an infection at a distant site, usually GI or genital

Typically affects the lower limb

Epidemiology

In males who are HLA-B27 positive they have a 30-50 fold increased risk

Women are LESS COMMONLY AFFECTED

Main Causes

GI infections

Sexually acquired

Shigella

Yersinia enterocolitica

Salmonella

Urethritis from chlamydia trachomatis

Ureaplasma urealyticum

Pathophysiology

Bacterial antigens or bacterial DNA have been found in the inflamed synovial of affected joints - suggesting that his persistent antigenic material is driving the inflammatory response

Clinical Presentation

Circinate balanitis - painless ulceration of the penis

Enthesitis - common

Acute anterior uveitis

In those who are HLA-B27 positive - sacroilitis & spondylitis

The arthritis may be the presenting complaint if the infection is mild or asymptomatic

Sterile conjunctivitis occurs in 30%

Occurring a few days to a couple of weeks after the infection

Skin lesions resemble psoriasis

Arthritis is typically an acute, ASYMMETRICAL, lower-limb arthritis

Diagnosis

Treatment

Sexual health review

Aspirated synovial fluid is sterile with high neutrophil count - if the joint is hot and swollen can exclude crystal arthritis

Culture stool if diarrhoea

X-ray may show enthesitis

ESR & CRP raised in acute phase

Screen sexual partners

Treat persisting infections with antibiotics

Joint inflammation - NSAIDs and corticosteroid injections

Majority of individuals with reactive arthritis have a single attack and it settles, but a few develop disabling relapsing and remitting arthritis

If relapse - use METHOTREXATE or SULPHASALAZINE

If that doesn't work, use TNF-alpha blockers but rarely necessary