Physical Exam Findings of Pyloric Stenosis
The classic physical exam finding in pyloric stenosis is a palpable olive-shaped mass in the epigastrium, though this finding is becoming less common with earlier diagnosis through imaging. 1, 2, 3
Key Physical Examination Findings
Palpable Pyloric "Olive"
- An olive-shaped, firm muscular tumor palpable in the epigastrium is pathognomonic for hypertrophic pyloric stenosis 4, 2
- The mass is typically felt in the right upper quadrant or epigastric region 4
- This finding alone is sufficient to confirm the diagnosis without further imaging in experienced hands 2
- However, the frequency of detecting this classic finding has declined significantly over time - recent studies show the pyloric olive is not palpable in approximately 50% of cases, compared to higher detection rates in older literature 3
- This decline correlates directly with earlier utilization of imaging studies (particularly ultrasound) rather than a true change in disease presentation 3
Visible Gastric Peristalsis
- Vigorous gastric peristaltic waves may be visible across the abdomen after feeding 4, 3
- These waves move from left to right across the upper abdomen as the stomach attempts to overcome the pyloric obstruction 4
Signs of Dehydration
- Physical examination may reveal signs of dehydration including decreased skin turgor, dry mucous membranes, and sunken fontanelle 1, 4
- Dehydration severity has decreased in recent cohorts due to earlier diagnosis 1
Clinical Context
Changing Clinical Presentation
- The age at diagnosis has increased slightly in recent years (from mean 37 days to 43 days), though classical symptoms remain consistent 1
- The decrease in palpable pyloric masses reflects declining clinical examination skills and earlier resort to imaging rather than an actual change in disease pathology 3
- When an experienced examiner detects a palpable olive in a patient with typical symptoms (projectile vomiting), no confirmatory imaging is required 2
Important Caveats
- Delayed or inadequate physical examination leads to overutilization of imaging and potential diagnostic delays 2
- The absence of a palpable mass does not exclude pyloric stenosis - ultrasound should be performed when clinical suspicion remains high 5, 6
- Physical examination should be performed by an experienced examiner, ideally after gastric decompression, as a distended stomach can obscure the pyloric mass 2