Paediatrics: Adrenal excess

Adrenal excess

A state of glucocorticoid (cortisol) excess. The commonest cause of hy-percortisolaemia is iatrogenic, due to exogenous steroids. Hyperfunction of the adrenal cortex resulting in excess cortisol secretion may have p (adrenal or ACTH-independent) or s (ACTH-dependent) causes. The term Cushing’s disease applies to an ACTH-secreting pituitary tumour. All other causes of glucocorticoid excess are often referred to as Cushing’s syndrome.

Causes of adrenal (cortisol) excess

·  Iatrogenic.

·  p adrenal hyperfunction (ACTH-independent):

·  adrenal tumour (carcinoma/adenoma);

·  nodular adrenal hyperplasia;

·  McAS.

·  s adrenal hyperfunction (ACTH-dependent):

·  Cushing’s disease—pituitary ademona/hyperplasia;

·  ectopic ACTH secretion (tumour).

In young children (<5yrs) adrenal disorders are the most common, non-iatrogenic, cause of hypercorticolism. In neonates and infants, McAS should be considered. In older children and adolescents Cushing’s disease is most common.

Clinical features

All causes of hypercortisolaemia are characterized by the following pat-tern of clinical signs and symptoms.

·  Obesity: central adiposity—face, trunk, abdomen.

·  ‘Moon’ faecies.

·  Buffalo hump: prominent/enlarged posterior cervical/supraclavicular fat pads.

·  Muscle wasting.

·  Proximal muscle weakness.

·  Skin abnormalities: thinning (rare in children); easy bruising; striae (abdomen/thighs).

·  Hypertension.

·  Growth impairment: reduced growth velocity; short stature.

·  Pubertal delay/amenorrhoea.

·  Osteoporosis.

Note: Other signs may be present depending on the underlying cause. Children with adrenal tumours may have signs of abnormal virilization and masculinization (early pubic hair, hirsuitism, acne, clitoromegaly) due to excess adrenal androgen secretion.

Investigations

These are directed at establishing a diagnosis of hypercortisolism and thereafter at differentiating between ACTH-dependent and ACTH-independent causes.

Management

Cushing’s disease

·Preoperative treatment in order to normalize blood cortisol levels:

·  metyrapone;

·  ketaconazole.

·Pituitary surgery: transsphenoidal surgery.

·Pituitary radiotherapy.

Adrenal disease/tumour

·Surgery, i.e. adrenalectomy.