Seronegative spondyloarthropathies

• Conditions affecting the spine and peripheral joints which cluster in families and are associated with HLA-B27

Ankylosing spondylitis

• Episodic inflammation of the spine and sacroiliac joints
• Asymmetrical large joint arthritis
• HLA-B27 in >90%
• Associated with uveitis and costochondritis
• Inflammatory markers elevated
• X-rays
• Erosions and sclerosis of affected joints
• Syndesmophytes
• Bamboo spine
• Treated with preventative exercises and NSAIDs, TNF-alpha blocking drugs if severe
• Infliximab and etanercept

Psoriatic arthritis

Clinical features

• Arthritis in association with psoriasis
• May predate skin lesions
• DIP most common joints affected
• Dactylitis
• Erosions on X-rays (centre of joint unlike juxta-articular erosions in RA)
• 5% have arthritis mutilans
• Nail dystrophy in 85% of cases
• HLA-B27 in 50%

Management

• Treated with
• NSAIDs
• Steroid injections to joints
• Sulfasalazine
• Methotrexate/ciclosporin
• TNF-alpha blocking drugs, e.g. Infliximab

Reactive arthritis

• Sterile synovitis following dysentery or a sexually acquired infection

Aetiology

• Trigger organism
• Salmonella
• Shigella
• Yersinia
• Chlamydia
• Ureasplasma

Clinical features

• Acute symmetrical lower limb arthritis
• Male more than female
• Often also an enthesitis e.g. plantar faciitis
• Non-articular features
• Acute anterior uveitis
• Circinate balanitis
• Keratoderma blenorrhagica
• Nail dystrophy
• Conjunctivitis
• Reiter's disease = urethritis, arthritis, and conjunctivitis

Management

• Treatment usually symptomatic with NSAIDs or steroid injections
• Treat underlying infection with antibiotics

Inflammatory bowel disease (IBD) - associated arthritis

• 10-15% of patients with IBD
• Lower limb joints
• In UC treatment of bowel disease may improve arthritis
• In Crohn's disease arthritis persists even when bowel is disease inactive
• 5% have sacroiliitis (independent of activity of IBD)
• Treatment with intra-articular steroids and sulfasalazine

Gout

• Inflammatory arthritis associated with hyperuricaemia and urate crystal deposition

Epidemiology

• 5% of the population have hyperuricaemia
• 0.2% of the population have gout
• Male > female
• Commonly presents between 30 and 50 years
• Rare in women before the menopause
• Familial or sporadic
• HLA-DR4 positive in 50-70%

Aetiology

• Causes of hyperuricaemia

Clinical features

• Acute onset
• Acute painful, red, swollen joint
• Often affects first MTP joint
• Precipitated by
• Alcohol
• Excess food
• Dehydration
• Diuretics

Investigations

• Joint fluid microscopy - needle shape crystals
• Serum urate
• Urea and electrolytes

Management

• NSAIDs
• Colchicine (particularly if NSAIDs cannot be used)
• If attacks are frequent give allopurinol to reduce urate 4-6 weeks after acute attack
• Lifestyle advice, e.g. diet, reduce alcohol intake

Chronic tophaceous gout

• Very high serum urate
• White urate deposits (tophi) in skin particularly ear lobes and around joints
• Associated with renal failure or use of diuretics