title: Hyponatremia in a Teenager: A Rare Diagnosis.
abstract: BACKGROUND
  Hyponatremia is a common electrolyte alteration which has the potential for significant morbidity and mortality. Endocrine disorders, such as primary hypothyroidism and adrenal insufficiency are uncommon causes of hyponatremia. We present the case of a teenager with symptomatic hyponatremia caused by a rare disorder.
  
  
  METHODS
  A 17-year-old boy was admitted to the emergency department with abdominal pain, nausea and vomiting, asthenia, and weight loss. He was in poor general condition, hypotensive, and he had dry mucous membranes and skin as well as mucosa hyperpigmentation. The laboratory findings showed severe hyponatremia, hyperkalemia, and renal dysfunction. The patient started inotropic support and antibiotics. Plasma cortisol and corticotropin levels allowed the diagnosis of primary adrenal insufficiency. He began replacement therapy with hydrocortisone and fludrocortisone, with gradual symptom resolution. An abdominal computed tomography scan showed adrenal hypoplasia. Findings for antiadrenal and antithyroid antibodies were positive, allowing the diagnosis of autoimmune polyglandular syndrome type II.
  
  
  CONCLUSIONS
  Adrenal insufficiency is a rare disease, especially in children, and its clinical manifestations are due to glucocorticoid and mineralocorticoid deficiency. In most of the cases, symptoms are nonspecific, requiring a high index of clinical suspicion. If the diagnosis and treatment are delayed, acute adrenal insufficiency carries a high morbidity and mortality.
authors.affiliation: From the *Pediatric Department, Centro Hospitalar do Alto Ave, Guimarães; †Pediatric Department, Centro Hospitalar do Porto; ‡Pediatric Intensive Care Unit; and §Pediatric Department-Pediatric Endocrinology, Centro Hospitalar de São João EPE, Porto, Portugal.
authors.forename: Filipa
authors.initials: F
authors.lastname: Correia
authors.forename: Alexandre
authors.initials: A
authors.lastname: Fernandes
authors.forename: Teresa C
authors.initials: TC
authors.lastname: Mota
authors.forename: Milagros
authors.initials: M
authors.lastname: Garcia
authors.forename: Cíntia
authors.initials: C
authors.lastname: Castro-Correia
authors.forename: Manuel
authors.initials: M
authors.lastname: Fontoura
authors.forename: Augusto
authors.initials: A
authors.lastname: Ribeiro
mesh_terms: D000224:Addison Disease / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D000293:Adolescent; D000324:Adrenocorticotropic Hormone / Q000097:blood; D000450:Aldosterone / Q000097:blood; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D004338:Drug Combinations; D005438:Fludrocortisone / Q000627:therapeutic use; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000627:therapeutic use; D007010:Hyponatremia / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology; D007262:Infusions, Intravenous; D008297:Male; D014057:Tomography, X-Ray Computed
chemical_list: D000893:Anti-Inflammatory Agents; D004338:Drug Combinations; D000450:Aldosterone; D000324:Adrenocorticotropic Hormone; D005438:Fludrocortisone; D006854:Hydrocortisone