Allergic gastroenteritis hospital admission time trends in Australia and New Zealand

Aim: Recent epidemiological studies indicate increases in hospital food allergy-related anaphylaxis admission rates in Australian and New Zealand. The aim of the study was to examine whether non-IgE-mediated food allergy might have increased in parallel. Methods: We analysed childhood hospital admissions rates by ICD 10 codes for allergic gastroenteritis (AG) and infective gastroenteritis in Australia and New Zealand between June 1998 and July 2014. Results: In Australia, most AG-related admissions (73%) occurred in those aged <1 year and increased by 7.3%/year (95% confidence interval (CI) 5.5–9.3, P < 0.0001) from 6.8 to 26.5/10⁵ population. Similar trends were observed for New Zealand; 81% of admissions occurred in those aged <1 year and increased by 9.4%/year (95% CI 5.5–9.3, P < 0.0001) from 7.2 to 30.7/10⁵ population. By contrast there were no significant changes in AG-related admission rates in the older patients and infective gastroenteritis admissions fell in both countries in those aged <1 year; Australia by 4.4%/year (95% CI 4.3–4.6, P < 0.0001) and in New Zealand by 5.8%/year (95% CI 5.4–6.2, P < 0.0001). Conclusion: We observed a fourfold increase in AG-related admission rates in two countries with known high rates of IgE-mediated food allergy/anaphylaxis. If confirmed by other studies, it will be of interest to determine if factors thought to contribute to the increase in IgE-mediated food allergy might also play a role in non-IgE-mediated gastroenterological food allergy syndromes.