Systemic Sclerosis (Scleroderma) and CREST

Background

  • Generalised disorder of connective tissue affecting the skin, internal organs and vasculature; characterised by sclerodactyly in combination with Raynaud’s and digital ischaemia
  • Peak age is 40-60; prevalence 10-20/100,000; much more common in women (4:1)
  • Can be classified as diffuse cutaneous (DCSS) (30%) or limited cutaneous (LCSS- restricted to below elbow/knee and face) (70%)
    • LCSS patients often have features grouped into the ‘CREST‘ syndrome
      • Calcinosis
      • Raynaud’s
      • oEsophageal involvement
      • Sclerodactyly
      • Telangiectasia
  • Prognosis of DCSS is poor (70% at 5 years from diagnosis)
    • Risk factors include age, diffuse skin disease, proteinuria, high ESR/PV; low TLCO and pulmonary hypertension

Aetiology/Pathophysiology

  • Cause is poorly understood- genetic component likely
  • Clear evidence of immune dysfunction: T-lymphocytes infiltrate the skin causing abnormal fibroblast activation and increased production of extracellular matrix in the dermis (mainly type I collagen)
    • Results in thickening, tightening and induration of the skin; narrowing of the arterial/arteriolar walls
  • There is also endothelial injury which causes vasoconstriction and platelet activation which causes yet further ischaemia and exacerbate fibrosis

Presentation

  • Non pitting oedema of the fingers and flexor tendon sheaths, progressing to taut skin (shiny appearance with disappearance of the the skin creases)
    • Thinning of the lips and radial furrowing
  • Erythema and tortuous dilation of nail-bed capillaries
  • Reynaud’s phenomenon
  • Arthralgia, morning stiffness and flexor tenosynovitis
    • Muscle weakness and wasting can occur due to myositis
  • Reflux and erosive oesophagitis (lower third oesophageal involvement); dysphagia and odynophagia; upper GI bleeding (watermelon stomach, or antral vascular ectasia- 20%); (pseudo-)obstruction
  • Hypertension

Investigations

  • Clinical diagnosis but ESR/PV and IgG level are usually high
    • CRP can be normal
  • ANA positive in 70%
    • DCSS are topoisomerase 1 antibody positive in 30%
    • LCSS are anticentromere antibody positive in 60%

Management

  • Symptomatic treatment
    • Reynauds
      • Avoid cold and calcium channel blockers
      • Prostacyclin infusion may help digital ischaemia
    • Oesophageal problems
      • PPI and anti-reflux agents
      • If there is obsructive problems- metoclopramide/domperidone may be helpful
    • Hypertension
      • Treat aggressively with ACE inhibitor
    • Joints
      • Analgesia and/or NSAIDs (although consider renal function)
    • Pulmonary hypertension
      • Bosentan
      • Heart-lung transplant
      • Steroids if there is co-existing myositis/fibrosing alveolitis

Complications

  • Frequently causes oesophageal dysmotility leading to recurrent aspiration pneumonia.
  • Pulmonary hypertension (common complication of long-standing disease and presents with rapidly progressive dyspnoea, right heart failure and angina), pleuritis, pneumothorax and occasionally pulmonary haemorrhage and fibrosing alveolitis
  • Rarely, patients develop malignant hypertension and renal crisis
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