Oxalate Concentrations in Human Gastrointestinal Fluid.

Primary adrenal insufficiency, or Addison’s disease, is a rare but potentially life-threatening disorder in children, most often caused by autoimmune destruction of the adrenal cortex []. Autoimmune Addison’s disease (AAD) may occur as an isolated condition or as part of autoimmune polyendocrine syndrome (APS), particularly APS type 1 (APS-1) or type 2 (APS-2) []. The clinical spectrum of adrenal insufficiency in paediatrics includes hyperpigmentation, fatigue, weight loss, gastrointestinal disturbances, electrolyte abnormalities, and hypoglycaemia []. Prompt recognition is essential, as adrenal crises are a major cause of morbidity and mortality in these patients []. APS comprises a heterogeneous group of conditions defined by the coexistence of multiple autoimmune diseases affecting endocrine and other organ systems []. APS-1, usually caused by pathogenic variants in the gene, typically presents in childhood with the triad of chronic mucocutaneous candidiasis, hypoparathyroidism, and adrenal insufficiency []. APS-2 generally manifests later (in adolescence or adulthood) and involves Addison’s disease in combination with autoimmune thyroid disease and/or type 1 diabetes mellitus []. There is a significant gap in the literature on paediatric AAD, especially in the Middle East, including Iraq. Early diagnosis and appropriate management of AAD are critical to prevent life-threatening adrenal crises, yet regional data are scarce [–]. Factors such as atypical aetiologies, variable clinical presentations, diagnostic delays, and underlying genetic diversity pose challenges to care in this region. In this context, we conducted a 15-year retrospective study at the Children’s Welfare Teaching Hospital in Baghdad, Iraq, to characterize and compare the demographic, clinical, and laboratory features of children with isolated AAD versus those with APS. By defining the distinguishing features of these two patient groups, we aim to enhance clinical recognition, guide more effective management strategies for paediatric adrenal insufficiency, and contribute to the understanding of these rare diseases in our region.