Cystic Fibrosis

A genetic disease of thick secretions, now transformed by CFTR modulators

Pediatrics

The basics

Autosomal recessive (CFTR gene). Two carrier parents: 25% chance each pregnancy.
Thick, sticky secretions block the lungs, pancreas, intestines, liver and reproductive tract.

Signs

Meconium ileus at birth (often the first sign).
Salty-tasting skin.
Poor growth despite a big appetite; bulky, greasy, foul-smelling stools (steatorrhea).
Chronic cough, repeated lung infections (Staph aureus, Pseudomonas), clubbing, nasal polyps.
Most males are infertile (absent vas deferens).

Diagnosis

Newborn screening (IRT blood test) → sweat chloride test.
Sweat chloride ≥60 mmol/L = CF; 30–59 = intermediate (needs more testing).
Genetic testing confirms the mutations.

CFTR modulators New

Fix the faulty protein for most mutations: elexacaftor/tezacaftor/ivacaftor (Trikafta) from age 2, and vanzacaftor/tezacaftor/deutivacaftor (Alyftrek) from age 6. Big gains in lung function, weight and survival. Monitor liver tests and eye exams (cataracts in children).

Lungs: airway clearance every day

Chest physiotherapy, oscillating vest or PEP device, huff coughing, exercise: usually 1–2+ times a day.
Usual order: bronchodilator → hypertonic saline → dornase alfa → airway clearance → inhaled antibiotic (e.g., tobramycin) → inhaled steroid if used.
Airway clearance before meals (or 1 h after) to avoid vomiting.
Infection control: people with CF keep ≥6 ft (2 m) apart from each other (cross-infection); contact precautions in hospital.

Pancreas and nutrition

Pancreatic enzymes (pancrelipase) with every meal and snack, at the start of eating.
Swallow capsules whole, or open and sprinkle beads on a small amount of acidic soft food (applesauce). Don't crush or chew the beads; don't mix with milk.
Adjust dose to stools (fewer greasy stools = right dose).
High-calorie, high-protein, high-fat (unrestricted fat) diet, individualized (some people on modulators now gain too much weight); extra salt in hot weather, fever or exercise.
CF-specific fat-soluble vitamins A, D, E, K.

Complications

CF-related diabetes (yearly screening from age 10) · distal intestinal obstruction · liver disease · low bone density · pneumothorax · hemoptysis · depression and anxiety (screen).

Memory hook Salty, skinny, stinky, sticky: salty skin, poor growth, greasy stools, thick mucus.