Cystic fibrosis

Question 1

What is cystic fibrosis?

Answer 1

Autosomal recessive genetic condition affecting mucosal glands
CFTR protein mutation (delta f508 mutation) on chromosome 7 leading to viscous mucus secretions

Question 2

Features of cystic fibrosis?

Answer 2

Thick secretions and blockage in pancreatic and bile ducts (leading to diabetes, liver disease, pancreatitis)

Thick airway secretions (leading to chronic cough, LRTIs

Bilateral absence of vas deferens (leading to male infertility)

Question 3

How does cystic fibrosis present in neonates, infants, toddlers, and children?

Answer 3

In neonates:
Meconium ileus, treated with gastrograffin enema

In infants:
Salty sweat
Failure to thrive
Recurrent chest infections
Diarrhoea

Toddlers:
Failure to thrive
Recurrent chest infections
Malabsorption syndrome

Children:
Delayed puberty
Bronchiectasis
Malabsorption
Recurrent chest infections
URTI

Question 4

Management of meconium ileus?

Answer 4

Gastrograffin enema

Question 5

How does meconium ileus present?

Answer 5

No passing of stool within 24 hours
Abdominal distension
Vomiting

Question 6

3 causes of clubbing in children?

Answer 6

Cystic fibrosis
Cyanotic heart disease
IBD

Question 7

Signs of cystic fibrosis?

Answer 7

Low weight and height on growth charts
Nasal polyps
Finger clubbing
Crackles and wheezes on auscultation
Abdominal distention

Question 8

What are the investigations to diagnose Cystic Fibrosis?

What further investigations can you do?

Answer 8

Diagnostic investigations…
Screening - Newborn bloodspot test
Diagnostic - Sweat test (Cl- conc. > 60mmol/L is positive for CF)
Genetic testing for CFTR gene

Further investigations…
Sputum culture
Stool elastase for pancreatic insufficiency diagnosis
Spirometry via FEV1 is indicator of life expectancy and severity
CT thorax for bronchiectasis

Question 9

Management of cystic fibrosis?

Answer 9

CFTR modulators, e.g. Kaftrio
Prophylactic flucloxacillin up to age 3yo to reduce Staph aureus risk
Daily chest physio for mucus clearance
Salbutamol
Mucolytics, e.g. Dornase alfa, hypertonic saline
Creon for pancreatic enzyme replacement
High calorie diet
Regular COVID, pneumococcal influenza vaccine
Bilateral lung transplant

Question 10

Most common bacterial colonisations in Cystic Fibrosis?

Answer 10

Staph aureus
Pseudomonas aeruginosa