🔑 Key Learning

  • Autoimmune connective tissue disease → skin thickening + organ fibrosis
  • 3 subtypes: Limited cutaneous, Diffuse cutaneous, Localised (morphoea/scleroderma)
  • ANA +ve in 90% of cases
  • Key complications: ILD, pulmonary hypertension, renal crisis
  • Key antibodies: Anti-centromere (limited), Anti-Scl-70 (diffuse)

🧬 Pathophysiology

  • Excess collagen production → skin fibrosis + internal organ involvement
  • Vascular abnormalities → Raynaud’s, pulmonary hypertension
  • Autoantibody-mediated (ANA, Anti-centromere, Anti-Scl-70)

👩‍⚕️ Limited Cutaneous Systemic Sclerosis (lcSSc)

👀 Clinical Features

  • Sclerosis affects the face & distal limbs
  • More gradual onset
  • Raynaud’s often precedes other symptoms
  • CREST syndrome:
    • Calcinosis
    • Raynaud’s
    • Esophageal dysmotility
    • Sclerodactyly
    • Telangiectasia
Figure 219: Shiny, tight skin on distal phalanges in systemic sclerosis. Maria Sieglinda von Nudeldorf, CC BY-SA 4.0

🧪 Antibodies

  • Anti-centromere antibody
  • ANA +

🧍‍♀️ Diffuse Cutaneous Systemic Sclerosis (dcSSc)

👀 Clinical Features

  • Affects trunk and proximal limbs
  • Rapid onset skin thickening
  • More aggressive course

💣 Complications

  • Interstitial lung disease (SSc-ILD) – dyspnoea, cough, fibrosis
  • Pulmonary hypertension
  • Renal crisis – accelerated hypertension + AKI
  • Cardiac involvement – arrhythmias, myocarditis
Figure 220: HRCT image demonstrating interstitial lung disease in a patient with diffuse cutaneous systemic sclerosis. Nevit Dilmen, CC BY-SA 3.0.

🧪 Antibodies

  • Anti-Scl-70 (anti-topoisomerase I)
  • ANA +

🧴 Localised Scleroderma (Morphoea)

👀 Clinical Features

  • No systemic involvement
  • Localised skin thickening only
  • Plaque morphoea: oval, discoloured, shiny lesions
  • Linear morphoea: thickened bands/lines on arms, legs or face

📝 Exam Clues & Clinchers

  • Raynaud’s + shiny skin on fingers → Limited cutaneous systemic sclerosis (CREST)
    • Check anti-centromere antibodies
  • Truncal skin thickening + ILD → Diffuse cutaneous systemic sclerosis
    • Check anti-SCL-70 antibodies
  • Oval shiny skin patch, no systemic signs → Localised morphoea (scleroderma)
  • Anti-centromere + CREST → Limited cutaneous SS
  • Anti-Scl-70 + ILD + proximal involvement → Diffuse cutaneous SS