Adult-onset Still's disease

Background

• Inflammatory condition of unknown etiology characterized by fever, rash, and arthritis

Clinical Manifestations

• The classic triad includes fevers, joint pain, and a maculopapular salmon-colored rash
  • Arthritis or arthralgia: usually knees, wrists, and ankles
  • Rash: evanescent, salmon‐pink, maculopapular eruption, predominantly found on the proximal limbs and trunk
  • Fever: over 39°C, transient, lasting typically under 4 hours
• Sore throat
• Myalgia
• Lymphadenopathy
• Splenomegaly
• Pleuritis
• Pericarditis

Differential Diagnosis

• Reactive arthritis
• Other spondyloarthropathies
• Haemophagocytic syndrome
• Dermatomyositis
• Kikuchi syndrome
• Sweet syndrome
• Granulomatous disorders
• Vasculitis
• Periodic fever syndromes
  • Familial Mediterranean fever
  • TNF receptor associated periodic syndrome (TRAPS)

Investigations

• RF and ANA, which should be negative
• Elevated ferritin, typically over 1000
• CBC may show leukocytosis, anemia, thrombocytosis
• Elevated liver enzymes and LDH

Management

• NSAIDs, corticosteroids, and antirheumatic agents