Endocrine Disorders in Children

Endocrine Disorders in Children

• Endocrine disorders in children involve various glands, including pineal, hypothalamus, pituitary, thyroid, parathyroid, thymus, adrenal, pancreas, ovary (female), and testis (male).

Hypothalamic-Pituitary System

• The pituitary gland is a midline structure below the hypothalamus in the pituitary fossa.
• It has three lobes: anterior, posterior, and a small intermediate lobe.
• The anterior and intermediate lobes develop from the buccal mucosa.
• The posterior lobe arises from neural ectoderm.
• Five anterior pituitary cell types are defined by their hormones:
  • Corticotrophs (ACTH)
  • Somatotrophs (GH)
  • Gonadotrophs (LH, FSH)
  • Thyrotrophs (TSH)
  • Lactotrophs (Prolactin or PRL)
• The posterior pituitary secretes oxytocin and antidiuretic hormone.

Pituitary Disorders

• Congenital:

  • Agenesis of the corpus callosum
  • Structural abnormalities (septo-optic dysplasia)
  • Pituitary hypoplasia
  • Idiopathic hormonal abnormalities (isolated GH deficiency, idiopathic precocious puberty)

• Acquired:

  • Excess: Intracranial tumors, Cushing disease (pituitary adenoma)
  • Deficiency: Pituitary damage, tumors, surgery, radiotherapy, trauma (secondary to treatment with radiation or surgery)

Posterior Pituitary Disorder: Syndrome of Inappropriate ADH Secretion (SIADH)

• Caused by high ADH levels without normal physiologic stimuli for release.
• Leads to water retention, increased total body water, decreased aldosterone production, solute loss (Na+), hyponatremia, and hypo-osmolality.
• Resulting symptoms include thirst, anorexia, dyspnea on exertion, and fatigue.

Posterior Pituitary Disorder: Diabetes Insipidus (DI)

• Related to ADH insufficiency, resulting in polyuria and polydipsia.
• Types:
  • Neurogenic/central DI: reduced ADH production
  • Nephrogenic DI: inadequate response to ADH (increased plasma osmolality → thirst → polydipsia).
  • Symptoms include increased urine output, low urine specific gravity (1.00-1.005), and dehydration.

Diseases of the Anterior Pituitary Gland

• Disease presentation depends on the affected hormones. If all hormones are deficient, it is called panhypopituitarism.
• Deficiencies often manifest with symptoms specific to each hormone's function (e.g. ACTH deficiency symptoms include nausea, vomiting, anorexia, fatigue, weakness, and hypoglycemia).

Adrenal Disorders

• Congenital Adrenal Hyperplasia (CAH): Common cause of insufficient cortisol and mineralocorticoid secretion in children.
• About 70-80% with CAH are unable to produce aldosterone, leading to salt loss (low sodium and high potassium).
• Virilisation of external genitalia in female infants and clitoral hypertrophy, and variable fusion of the labia are symptoms.
• In the affected male infant, the penis may be enlarged and scrotum pigmented.
• Diagnosed by measuring elevated metabolic precursor 17-hydroxyprogesterone levels in blood.
  • Biochemical abnormalities in salt losers include low plasma sodium, high plasma potassium, and metabolic acidosis.

Adrenal Disorders: Primary Adrenal Insufficiency (Addison's Disease)

• Rare in childhood, potentially caused by autoimmune processes, hemorrhage/infarction (neonatal or meningococcal septicemia), X-linked adrenoleucodystrophy, or tuberculosis.
• May also result from pituitary dysfunction or long-term corticosteroid therapy.
• Infants present with a salt-losing crisis, hypotension, and/or hypoglycemia.
• Older children may present with nonspecific symptoms such as fatigue and/or pigmentation.
• Diagnosing this requires identifying hyponatremia, hyperkalemia, metabolic acidosis, and hypoglycemia. Cortisol and ACTH levels are also assessed.

Cushing Syndrome

• Excess glucocorticoid caused typically by long-term glucocorticoid treatment.
• Other possibilities are Cushing disease (pituitary adenoma), or from ectopic ACTH producing tumors.
• Possible symptoms include growth failure, short stature, face and trunk obesity, red cheeks, hirsutism, striae, hypertension, bruising, carbohydrate intolerance, muscle wasting, weakness, osteopenia and psychological problems.
• Diagnosis includes identifying adrenal tumor (unilateral), and elevated cortisol levels that don't decrease after a dexamethasone test.

Hyperparathyroidism

• In neonates and young children, it's typically linked to rare genetic abnormalities like William Syndrome.
• In older children, it's secondary to adenomas or part of multiple endocrine neoplasia syndromes.
• It presents with high calcium causing constipation, anorexia, lethargy, behavioral effects, polyuria, and polydipsia.
• Bony erosions in the phalanges might show up in hand radiographs.

Hypoparathyroidism

• Rare in childhood, causing low serum calcium levels but raised serum phosphate, and normal alkaline phosphatase.
• Often caused by DiGeorge syndrome, and associated with defective immunity, cardiac defects, and facial abnormalities in infants. In children, it can be an autoimmune disorder, sometimes linked with Addison's disease.
• Severe hypocalcemia leads to muscle spasm, fits, stridor, and diarrhoea. Presentation may also include pseudohypoparathyroidism.
• Presentation symptoms include short stature, obesity, subcutaneous nodules, short metacarpals, teeth enamel and learning difficulties, and basal ganglia calcification.

Hypothyroidism

• TSH deficiency results in symptoms occurring within weeks: cold intolerance, dryness of skin, mild myxedema, lethargy and precocious puberty.

FSH and LH Deficiencies

• In reproductive age, symptoms involve delayed puberty, amenorrhea, and atrophic changes in the vagina, uterus, and breasts in females.
• Testicular atrophy in males.

Hyperpituitarism

• Excess hormone production from adenoma (e.g. prolactinoma, acromegaly). Often less common in children than adults.

Treatment of Conditions

• Adrenal Crisis: Intravenous saline, glucose, and hydrocortisone. Long-term treatment with glucocorticoid and mineralocorticoid replacement adjusting doses based on an illness or surgery. Parents learn to inject intramuscular hydrocortisone.
• Hypocalcemia: Intravenous calcium gluconate, and vitamin D analogues.
• Adrenal Tumors: Surgery (adrenalectomy), and radiotherapy.
• Pituitary Adenomas: Transsphenoidal resection, radiation therapy.

This quiz explores the various endocrine disorders affecting children, focusing on the key glands involved such as the pituitary, thyroid, and adrenal glands. It also delves into the hypothalamic-pituitary system and associated disorders. Learn about the functions, hormones involved, and the implications of congenital abnormalities.