Adult-onset Still's disease

Definition

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

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)

Clinical Presentation

• Sore throat
• Myalgia
• Fever over 39°C, transient, lasting typically under 4 hours
• Arthritis: usually knees, wrists, and ankles
• Arthralgia
• Lymphadenopathy
• Rash: evanescent, salmon‐pink, maculopapular eruption, predominantly found on the proximal limbs and trunk
• Splenomegaly
• Pleuritis
• Pericarditis

Investigations

• RF and ANA negative
• Elevated ferritin >1000
• Leukocytosis, anemia, thrombocytosis
• Elevated liver enzymes and LDH

Management

• NSAIDs, steroids, and antirheumatic agents