Rising incidence of paediatric scurvy – patient database querying does not reveal the whole story — authors’ reply

We appreciate the thoughtful comments from Oudiane and colleagues¹ regarding our study on scurvy incidence in French children and the trend changes associated with the COVID-19 pandemic.²

Oudiane and colleagues raised concern about the potential overestimation of scurvy incidence due to misclassification with asymptomatic vitamin C deficiency. Our study utilized the French Medicalization of Information Systems Program (PMSI), which is based on ICD-10 codes. While this database does not provide clinical symptom details, its rigorous quality control processes by the Department of Medical Information and the Technical Agency for Hospital Information likely minimize coding errors.³ To enhance specificity, we included only cases with ICD-10 code E54 as the principal diagnosis, indicating scurvy was the primary reason for hospitalisation. The short duration of hospitalisation we observed (median 4 days, mean 11 days) aligns with scurvy, as rapid improvement typically follows vitamin C supplementation.⁴

Although overestimation cannot be entirely ruled out, it is worth noting that the PMSI captures only hospitalised cases, potentially underestimating the true incidence, which includes outpatient and emergency cases. Importantly, the study primary objective was to analyse temporal trends—particularly changes associated with the pandemic—rather than determine precise incidence rates. Any over- or underestimation would not bias the observed association between the pandemic and the changes in scurvy trends.

Oudiane and colleagues suggested that increased vitamin C testing in asymptomatic patients might explain the observed rise in incidence. However, French guidelines in 2018 emphasized that vitamin C testing should be restricted to patients with clinically suggestive symptoms.⁵ Therefore, extensive vitamin C testing in hospital settings since the pandemic seems unlikely. Additionally, the absence of significant changes in the control outcomes (vitamin D deficiency and urinary tract infections) suggests that our results were not influenced by changes in the PMSI coding system.

Our findings strongly correlate scurvy incidence with socioeconomic precarity. The significant correlation between scurvy incidence and the food price indice (Spearman coefficient, 0.74; p < 0.001) underscores the impact of pandemic-driven food insecurity. Financial constraints, rather than food preferences, often limit access to adequate nutrition. Post-pandemic, universal health insurance coverage among scurvy patients rose by 32.7%, reflecting increased economic strain, higher than for other diseases. Reports from governments and NGOs indicate a notable rise in food insecurity between 2021 and 2023.⁶ Although initiatives extending beyond subsidized or free school meals have been implemented, these efforts, despite their benefits, are inconsistently implemented across France and have not effectively curbed the rise in scurvy cases.

We agree that other factors such as eating disorders may contribute to scurvy. In our cohort, 27.8% of hospitalised children with scurvy experienced malnutrition, while only 2.4% and 4.3% had feeding difficulties and autistic disorders, respectively. These findings highlight the multifaceted nature of the condition and the need for further research.

Despite limitations, our study leverages a robust nine-year dataset to analyse long-term national trends, revealing a troubling increase in paediatric scurvy in France. While scurvy remains rare, with an average monthly incidence of 0.1 cases per 100,000 children since March 2020, the significant rise associated with the pandemic underscores deepening social and economic inequalities affecting children's health. Addressing nutritional disparities and ensuring access to adequate nutrition are essential to safeguarding children's health—a fundamental right critical to societal well-being.

Contributors

ZA, AF, NO, and UM wrote the initial version of the manuscript. All authors revised and approved the manuscript.

Declaration of interests

We declare no competing interest.