Arthritis

Overview

Once arthritis is suspected, physicians should distinguish between noninflammatory and inflammatory forms of arthritis while recognizing potentially disabling and life-threatening problems.

Rule out septic arthritis in any monoarthritic presentation, prolonged diagnosis results in irreversible joint damage.

Definition

Polyarthralgia: multiple joint pain without synovities.
Polyarthritis: inflammation of 4 or more joints (synovitis).

Monoarthropathy	Oligoarthropathy	Polyarthropathy
Septic arthritis	Crystal arthritis	Rheumatoid arthritis
Crystal arthritis (Gout)	Psoriatic arthritis	Viral Arthritis
Osteoarthritis (can be mono-poly)	Reactive arthritis	Autoimmune connective tissue disease (ie. SLE)
Trauma (Haemarthrosis)	Ankylosing spondylititis	Vasculitides (ie. Polymyalgia Rheumatica)

Approach

History
- Sex
- Age of onset
- Pattern of arthritis
- Extra-articular features
- Which joints affected
  - peripheral symmetrical arthritis – Rheumatoid arthritis
  - Asymmetric with enthesitis and back pain – spondylarthritis
  - DIP joints with synovitis – psoriatic arthritis

Age
Child	Trauma, Congenital, slipped capital femoral epihpysis, Juvenile rheumatoid arthritis
Young Adults	Reactive arthritis, gonococcal, SLE
Older patients	Acute gout and Pseudogout, Rheumatoid arthrits

Examination
- Psoraiasis
- Malar rash – SLE
- Kerataderma blenorrhagica – Septic arthritis
- Salmon
Investigations

Differential Diagnosis

Arthritis can be divided into:

Acute or chronic
Monoarthritis, Oligoarthritis, Polyarthritis
Inflammatory and non-inflammatory
Seropositive or seronegative

Non-inflammatory Arthritis

Inflammatory Arthritis

Crystal arthropathy
Infectious
Seronegative arthritis
- Ankylosing spondylitis
- Psoriatic arthritis
- Reactive arthritis
- IBD arthritis
Seropositive arthritis
- Rheumatoid Arthritis
- Scleroderma
- Vasculitis
- Sjogren’s