Arthralgia/arthritis in adults

Question 1

Probability diagnosis

Answer 1

Osteoarthritis

Viral polyarthritis (e.g. hepatitis, parvovirus)

Question 2

Serious disorders not to be missed

Answer 2

Infection:

• rheumatic fever
• endocarditis
• tuberculosis
• brucellosis
• pyogenic (septic) arthritis: gonococcus, Staphylococcus, Kingella kingae
• HIV arthropathy
• dengue fever

Cancer:

• bronchogenic carcinoma
• leukaemia/lymphoma
• secondary malignancy

Other:

• rheumatoid arthritis (RA)
• CT disorders: SLE, scleroderma, polymyositis and dermatomyositis, other

Question 3

Pitfalls (often missed)

Answer 3

Spondyloarthropathies (e.g. psoriasis)

Fibromyalgia syndrome

Polymyalgia rheumatica

Crystal deposition:

• gout
• pyrophosphate (pseudogout)

Haemarthrosis

Dengue fever

Lyme disease

Ross River virus

Avascular necrosis

Rarities:

• other vasculitides (e.g. polyarteritis nodosa)
• haemochromatosis
• sarcoidosis
• Whipple disease
• hyperparathyroidism
• familial Mediterranean fever
• amyloidosis
• pigmented villonodular synovitis

Question 4

Masquerades checklist

Answer 4

Depression

Diabetes (?arthropathy)

Drugs: uncommon but some implemented

Thyroid disorder

Spinal dysfunction (spondyloarthropathies)

Question 5

Is the patient trying to tell me something?

Answer 5

Always a consideration with pain.

Psychogenic factors aggravate chronic arthritic conditions.

Question 6

Key history

Answer 6

There is such a multitude of causes of arthralgia that a skillful history to cover many angles is required.

1. Pattern of joint involvement (monoarticular or polyarticular)
2. immediate and more recent history
3. family hx
4. drug use.

Enquire whether the joint pain is acute or insidious and confined to specific joints or fleeting as in rheumatic fever.

Question 7

Key examination

Answer 7

look for signs of inflammation, deformity, swelling and limitation of movement.

Searching for associated systemic disease such as connective tissue disorders and infection demands examination of the chest, heart and abdomen.

Question 8

Key investigations

Answer 8

• FBE
• EBR & CRP
• Uric acid
• Urine analysis
• Joint X-rays
• Synovial fluid analysis and culture
• RA factor
• Autoantibodies (ANA, dsDNA, ENA), anti-CCP antibody (for RA)
• Other tests according to findings of tests for infection (e.g. specific serology, blood culture)

Question 9

Diagnostic tips

Answer 9

The commonest cause of arthritis is osteoarthritis (OA).

Other causes of monoarthritis include

• crystal deposition disease
• sepsis
• trauma
• spondyloarthritis.

The pain of inflammatory disease is worse at rest and improved by activity.

There should be no systemic manifestations with OA.

With polyarthritis (usually PIPs) and rash consider viral arthritis or a drug reaction.

Question 10

Red flag pointers for polyarthritis

Answer 10

• fever
• weight loss
• profuse rash
• lymphadenopathy
• cardiac murmur
• severe pain and disability
• malaise and fatigue
• vasculitic signs
• two or more systems involved