A 21-year-old female had recurrent presentations to the emergency department with myalgia, vomiting, abdominal pain and subsequently developed generalized seizures. She was volume depleted with a plasma sodium of 125 mmol/L (reference interval: 135-145) and she had fluctuating hypertension. Acute porphyria was suspected and confirmed with raised urine porphobilinogen/creatinine ratio of 12:4 μmol/mmoL (reference interval < 1:5) and she was treated with intravenous haem arginate. Urinary porphyrin/creatinine ratio was 673 nmol/mmoL (reference interval <35) and faecal porphyrins 2430 μmol/kg dry weight (reference interval: <200) were markedly elevated, with raised faecal CIII:CI ratio, consistent with acute coproporphyria. Diagnosis was confirmed by the demonstration of a novel missense variant in the coproporphyrinogen oxidase gene c.863T > G (p.Leu288Trp) predicted to be deleterious and which segregated with three other affected family members. Although CT head was normal, magnetic resonance imaging scan revealed symmetrical signal abnormalities and swelling in the parietal and occipital lobes consistent with posterior reversible encephalopathy. Over several days, her seizures ceased and sodium and blood pressure normalized. The aetiology of the acute porphyric attack was likely multifactorial with contributions from a recent viral illness and caloric deprivation. No drug precipitant was identified. We postulate that untreated hypertension played a key role in the development of posterior reversible encephalopathy. Early clinical suspicion and urine porphobilinogen testing are the key components in preventing morbidity and mortality in acute porphyrias.

Background Hospital admission for acute respiratory infections (ARIs) during early childhood is a global public health concern. Vitamin D deficiency is prevalent during pregnancy and infancy. Evidence indicates that vitamin D supplementation prevents ARIs. Objectives To determine whether vitamin D deficiency at birth is associated with ARI hospitalisations during infancy. Methods We performed a nested case–control study in children aged 0‐12 months. Cases had ≥1 ARI hospitalisation and 4 controls were individually matched to each case. Newborn 25(OH)D concentration was measured on dried blood spots using two‐dimensional liquid chromatography–tandem mass spectrometry. Hospital admissions were measured using health care records. Median serum 25(OH)D concentration in cases and controls was compared, and covariates of ARI hospitalisation during infancy were assessed using conditional logistic regression analysis. Results Six per cent of the cohort (n = 384) had an ARI hospitalisation during infancy, and 1536 controls were matched to cases. Median DBS [25(OH)D] was lower among ARI cases than controls (46 nmol/l vs. 61 nmol/L). Median 25(OH)D levels were lower for those hospitalised ≥2 times (47, IQR 36, 58) vs. those hospitalised once (52, IQR 42, 62) vs. the controls and also lower for those who stayed in the hospital for ≥3 days (45, IQR 36, 54) vs 1‐2 days (48, IQR 38, 59) compared to the controls. After adjustment for season of birth and covariates describing demographic, antenatal, perinatal, and infant characteristics, DBS 25(OH)D concentration (<50 nmol/L) at birth was associated with increased odds of ARI hospitalisation during infancy (odds ratio 2.20, 95% confidence interval 1.48, 2.91). Conclusions Vitamin D deficiency at birth is associated with increased odds of ARI hospitalisations in infants. The findings have implications for a developed country like New Zealand where vitamin D supplementation is not routinely recommended and the burden of ARI hospitalisation in young children is high.