From the Guidelines
Pyloric stenosis typically presents in infants between 2 and 8 weeks of age, with peak incidence around 3 to 5 weeks of life. This condition is characterized by progressive, forceful (projectile) vomiting that occurs after feeding, as noted in the evaluation of vomiting in infants 1. The timing of presentation is crucial for diagnosis, as pyloric stenosis rarely presents in the first week of life or after 3 months of age.
Key Considerations
- The condition is more common in male infants and firstborn children.
- The vomiting occurs because the pylorus muscle, which controls the passage of food from the stomach to the small intestine, becomes abnormally thickened, creating an obstruction.
- This leads to the characteristic symptoms of non-bilious projectile vomiting that progressively worsens over days to weeks.
- Parents may notice that their infant remains hungry after vomiting and is eager to feed again.
Importance of Early Recognition
If left untreated, the infant may develop dehydration, weight loss, and metabolic alkalosis due to loss of stomach acid through vomiting. Prompt recognition of the age of presentation and typical symptoms allows for timely surgical intervention with pyloromyotomy, which has excellent outcomes, as suggested by the clinical evaluation and diagnosis of gastrointestinal issues in infants 1.
Diagnostic Approach
A diagnostic workup should start with a thorough clinical evaluation, including history and physical examination, which can lead to the diagnosis in most instances 1. The classic “olive” of hypertrophied muscle may be felt upon examination, aiding in the diagnosis of hypertrophic pyloric stenosis (HPS).
Conclusion is not needed, the answer is complete as per the provided instructions.
From the Research
Age of Presentation for Pyloric Stenosis
- The age at which pyloric stenosis presents in infants can vary, with term infants typically presenting between 4 and 6 weeks of age 2.
- Premature infants may present at an older chronological age due to their prematurity, with a greater degree of prematurity associated with an older age of presentation 2.
- Some cases of pyloric stenosis may be diagnosed before 3 weeks of age, with these cases often having a shorter timeframe of diagnosis, a higher rate of jaundice, and a longer duration of hospital stay 3.
- The calculated postconceptional age for premature infants with pyloric stenosis is typically between 44 and 50 weeks 2.
Factors Influencing Age of Presentation
- Prematurity is a significant factor influencing the age of presentation for pyloric stenosis, with premature infants often presenting at an older age than term infants 2, 3.
- The degree of prematurity is also associated with an increased risk of postoperative morbidity, reintubation, readmission, and longer postoperative length of stay 2.