Infantile hypertrophic pyloric stenosis in a deprived region of South Wales
The study by T Sommerfield et al. (1) provides a valuable insight into the epidemiological trend of infantile hypertrophic pyloric stenosis (IHPS) in Scotland. It was interesting to note the proposed association between incidence of IHPS and deprivation.
We have recently reviewed cases of IHPS presenting to our hospital, which is a medium sized district general hospital serving a deprived population in the South Wales valleys. We were keen to assess the clinical presentation and our performance in terms of diagnosing and managing pyloric stenosis. A retrospective case review of all ultrasongraphically confirmed cases of pyloric stenosis over a seven year period (January 2000 to September 2007) was undertaken. Standards for notekeeping, clinical assessment,investigations and fluid management were derived from literature search and textbooks.
We found that majority of patients were term( 95%), first born( 100%), male infants( 90%) presenting between 2 - 10 weeks of life .Vomiting was the predominant presenting feature at median age of 24 days. No significant seasonal variation was noted. With a birth rate of about 2200/ year in our hospital the cumulative incidence of IHPS over the last 7 years amounts to 37 cases in 17,500 births which is about 2.1 per 1000 live births. 38% of infants were initially diagnosed to have Gastro Oesophageal reflux; however the time between initial presentation and surgical correction ranged from 2 to 3 days. Recovery was uneventful in 92% of the cases. Apart from one infant who had restenosis of the pylorus, complications in the rest were minor, responding to conventional treatment.
A study done in early 1980s by A R Webb et al.(2) showed that the incidence of surgically confirmed IHPS in the South Glamorgan region rose sharply after 1976 from 1.4/ 1000 live births to 3.6/ 1000 live births. This seemed to reflect epidemiological trends throughout Wales. Although there was speculation that this rise could be attributed to a change in feeding practises at that time (from formula to breast feeding), the data lacked statistical significance. Studies since exploring the relation between IHPS and maternal variables like breast feeding have been impeded by lack of sufficient data and tend to contradict each other (3, 4).
It was also interesting to note the association between IHPS and deprivation observed by the authors. Others have also suggested a relation between rural living and pyloric stenosis (5). Census has shown that Rhondda Cynon Taff suffers from high levels of economic and social deprivation with 67% of the total population living within the top third of the most deprived wards in Wales (6). Besides it also has a high proportion of rural population. Perhaps somewhat surprisingly the incidence of pyloric stenosis is only marginally different from the Scottish population. Social deprivation undoubtedly is an important contributor to the incidence of pyloric stenosis but it is probably just one of the many environmental variables determining the incidence of this fascinating condition.
1. The changing epidemiology of infantile hypertrophic pyloric stenosis in Scotland. T. Sommerfield et al. Arch Dis Child 2008; 93:1007- 1011.
2. Infantile hypertrophic pyloric stenosis in South Glamorgan 1970-9. Effects of changes in feeding practice. A R Webb et al. Arch Dis Child.1983 August; 58(8): 586–590
3. Breast feeding and hypertrophic pyloric stenosis: population based case-control study. Alfredo Pisacane et al. BMJ.1996 march; 312:745-746
4. Does Exclusive Breastfeeding Confer Protection Against Infantile Hypertrophic Pyloric Stenosis? A 30-year Experience in Benin City, Nigeria. David Osarumwese Osifo and Iyekoretin Evbuomwan.Journal of Tropical Pediatrics. 2008; 0: fmn094v1-fmn094.
5. Population demographic indicators associated with incidence of pyloric stenosis. T. To et al.Arch Pediatr Adolesc Med. 2005;159:520-525.
6. Welsh Index of Multiple deprivation 2008