Etiology of primary adrenal insufficiency in children: a 29-year single-center experience.

Background Primary adrenal insufficiency (PAI) in children is a rare condition and potentially lethal. The clinical characteristics are non-specific. It may be manifested as a chronic condition or crisis. The etiologies of PAI in children are different from the adult population. Therefore, diagnostic investigation becomes challenging. Methods A retrospective study was conducted at The First Affiliated Sun Yat Sen University Pediatric Endocrine unit between September 1989 and July 2016. Results A total of 434 patients (237 males, 197 females) were identified as having PAI. Congenital adrenal hyperplasia (CAH) was the most frequent etiology (83.4%, n = 362, male:female = 174:188), of which 351 (97.2%) were 21-hydroxylase deficiency (21-OH) CAH. Non-CAH etiology accounted for 11.3% (n = 49, male:female = 47:2), of which 46 (93.9%) were of non-autoimmune. The etiologies of the 49 cases were adrenoleukodystrophy (ALD; n = 22), X-linked adrenal hypoplasia congenital (X-AHC; n = 20), autoimmune polyglandular syndrome (APS; n = 3), triple A syndrome (n = 2), steroidogenic factor 1 (SF-1) gene mutation (n = 1) and adrenalectomy (n = 1). The etiology was not identified for 23 patients (5.3%, male:female =16:7). Clinical symptoms were in accordance with the incidence of genital ambiguity (42.6%), digestive symptoms (vomiting and diarrhea) (35.5%), failure to thrive (26.5%), gonadal-associated symptom (premature puberty, sexual infantilism and amenorrhea) (21.2%), hyperpigmentation (9.7%), adrenal crisis (AC; 4.1%), neurological symptoms (3.2%), fatigue (2.5%) and prolonged jaundice (2.1%). Through physical examination, 58.5% were found to have hyperpigmentation. Conclusions This study spanned 29 years at our institution. The etiology of PAI in children was mostly of congenital forms, which exhibits a wide spectrum of clinical characteristics. For etiological diagnosis, chromosomal karyotyping is recommended for female phenotype patients.