Cystic fibrosis

E84.9


DESCRIPTION

An autosomal recessive disorder of exocrine glands, mainly affecting the gut, pancreas and lungs.

DIAGNOSTIC CRITERIA

Clinical

  • Recurrent infections of the respiratory tract with later bronchiectasis, respiratory failure and cor pulmonale.
  • Bulky, greasy and foul-smelling stools.
  • Occasionally presents with constipation.
  • Malabsorption with weight loss and failure to thrive.
  • Meconium ileus.
  • Positive family history is uncommon unless cystic fibrosis is present in a sibling.

Investigations

  • Sweat test:
    • Quantitative analysis of sodium and chloride concentrations in sweat collected after stimulation by pilocarpine iontophoresis with chloride > 60 mmol/L.
    • Sweat conductivity tests are more readily available but not as reliable as sweat electrolyte testing. Positive range for conductivity is 90 mmol/L and above.
  • DNA analysis for delta F508 and a few other mutations. Negative mutation analysis does not exclude cystic fibrosis.
  • Stool elastase will be low in cystic fibrosis patients with pancreatic insufficiency.

GENERAL AND SUPPORTIVE MEASURES

  • Nutritional support.
  • Physiotherapy and postural drainage.
  • Psychosocial support.
  • Genetic counselling.

MEDICINE TREATMENT

Medicinal treatment is specialised and individualised and should be under the supervision of a subspecialist.

  • Pancreatic enzymes (lipase/amylase/protease), with meals according to clinical response.

REFERRAL

  • All to a recognised cystic fibrosis centre and/or specialist health facility for confirmation of diagnosis and initiation of treatment.
  • Management of exacerbations.