Vitamin D deficiency and rickets are important pediatric health concerns, particularly in high-latitude regions. This study investigated the incidence and clinical characteristics of pediatric vitamin D deficiency in Hokkaido, Japan, between 2015 and 2019. A cross-sectional survey was distributed to the pediatric departments of 88 major hospitals across the region, achieving a response rate of 97.7%. Clinical data were collected from 262 children with vitamin D deficiency (25(OH)D < 20 ng/mL), including 153 with rickets. In 2019, the incidence of vitamin D deficiency rickets was 25.4 per 100,000 live births, approximately threefold higher than 15 yr earlier and eightfold greater than the national average. Most cases (median age 1.4–1.5 yr) occurred in children younger than four years. Patients with rickets exhibited considerably lower Ca/P and higher ALP/iPTH levels than those without rickets, despite having similar 25(OH)D levels. Exclusive breastfeeding was significantly more common in the rickets group. Approximately 90% of patients received alfacalcidol. The incidence of pediatric vitamin D deficiency and rickets in Hokkaido has increased. These findings underscore the need for continued public health education on vitamin D intake, expanded access to native vitamin D supplementation, and attention to maternal vitamin D status.

Octreotide is considered a second-line treatment for congenital hyperinsulinism unresponsive to diazoxide. Necrotizing enterocolitis (NEC) is a serious adverse effect of octreotide, typically occurring in a dose-dependent manner. Here, we report a case of necrotizing enterocolitis following a single administration of a very low dose of octreotide. A female infant was admitted on day 3 of life with severe hypoglycemia. Laboratory findings revealed hyperinsulinemia and hypoketotic hypoglycemia, confirming a diagnosis of congenital hyperinsulinism. Despite diazoxide therapy, adequate glycemic control was not achieved. As a second-line intervention, a single subcutaneous injection of octreotide (1.6 μg/kg) was administered. Two days post-administration, the patient developed abdominal distension and significant vomiting. NEC was diagnosed, necessitating bowel decompression surgery. Subsequent 18F-DOPA positron emission tomography/computed tomography revealed a focal lesion extending from the pancreatic head to the body. The lesion was successfully resected with preservation of nearly the entire normal pancreas. This case highlights that even a very low dose of octreotide may precipitate necrotizing enterocolitis, warranting close monitoring. Lesion localization using 18F-DOPA positron emission tomography/computed tomography is critical in guiding surgical management of congenital hyperinsulinism.

Allgrove syndrome (AS), an uncommon multisystem disorder, is characterized by the classic clinical triad of alacrimia, achalasia, and adrenal insufficiency, and is typically limited to glucocorticoid deficiency with preserved mineralocorticoid (MC) function. Here, we present the case of a 5-yr-old girl with alacrimia since birth, failure to thrive, and generalized hyperpigmentation for the past two years, who presented to the emergency department with an altered sensorium. Upon admission, the patient was found to have hypoglycemia and hyponatremia. After subsequent evaluation, the patient was diagnosed with phenotypically incomplete AS with mineralocorticoid insufficiency and harbored a novel homozygous mutation in exon 7 of the AAAS gene (c.618del; p.Ser207LeufsTer84). Treatment with hydrocortisone and fludrocortisone yielded remarkable outcomes. Given the variable presentations of this condition, a high index of clinical suspicion and awareness of atypical features are essential for early diagnosis and initiation of coordinated care to prevent unnecessary morbidity and mortality. When AS is suspected, molecular genetic testing should be performed to confirm the diagnosis, plan management, and provide genetic counseling.