Epidemiology
- More common in boys (4:1)
- Often a maternal family history
- Increased risk if siblings were affected
- Erythromycin exposure in first few weeks of life
Pathology
There is a functional obstruction of the pyloric sphincter, as the muscle in this region hypertrophies. This ultimately results in almost complete obstruction.
Clinical features
Presents at 2-7 weeks of age – and is not related to gestational age
Projectile vomiting (non-bile stained), in an otherwise well child
- Typically occurs after each feed
- This increases in severity and frequency as the child continues to grow
- It really is projectile! – hits the walls / ceiling in some cases
- The child is usually otherwise well – in contrast to other causes of vomiting in neonates
- Obvious continued hunger despite vomiting. Only in the later stages when they are severely dehydrated will the child lose interest in feeding.
- Hypochloraemic alkalosis (metabolic alkalosis due to vomiting), and Hypokalaemia
- Failure to thrive / weight loss / poor weight gain
- Dehydration< Check for:
- Skin turgor
- Sunken eyes
- Moist mucous membranes
- When dehydration is marked and severe, the child may not be keen to feed
Diagnosis
- Milk Test – Give the child a normal milk feed. A wave of peristalsis should be visible across the abdomen from left to right
- Examination
- Pyloric olive – a 2-3cm mass that can sometimes be felt in the URQ. Usually mobile
- USS – Often used to confirm diagnosis of sphincter hyperplasia. Pylroci muscle usually >4mm thick (normal <2cm)
- Barium Meal – may be rarely used in cases when diagnosis is not certain. It will shows the string sign of an elongated and narrowed pyloric sphincter.
Treatment
- Initial Management – Correct fluid and electrolyte imbalances (if present)
- Surgery – Ramstedt pyloromyotomy – the excessive muscle is removed, but all gastric mucosa is left intact. Post-operatively the baby can usually feed normally within 24 hours of surgery
Flashcard
References
- Murtagh’s General Practice. 6th Ed. (2015) John Murtagh, Jill Rosenblatt
- Oxford Handbook of General Practice. 3rd Ed. (2010) Simon, C., Everitt, H., van Drop, F.
- Beers, MH., Porter RS., Jones, TV., Kaplan JL., Berkwits, M. The Merck Manual of Diagnosis and Therapy