Clinical presentation

• Hypoglycaemia (see Chapter 2).

• Collapse (see Chapter 13).

• Hypotension (see Chapter 14).

• Ambiguous genitalia (see Chapters 8 and 10).

• Skin pigmentation (commonly, but not exclusively, scrotal, see Chapter 11).

• Hyponatraemia (see Chapter 15).

Approach to the problem

• Assess perfusion.

• Measure blood pressure.

• Measure blood glucose.

• Measure blood sodium and potassium.

• Is there a history of asphyxia? (Bilateral adrenal haemorrhage.)

• History of maternal steroid excess (therapeutic administration or Cushing's syndrome).

Differential diagnosis

• Other causes of hypoglycaemia e.g. hyperinsulinism, or metabolic cause (see Chapters 2 and 3).

• Other causes of circulatory collapse, e.g. sepsis (see Chapter 13).

• Addisonian crisis (structural or functional absence of pituitary or adrenal glands).

Primary adrenal failure

• Congenital adrenal hyperplasia (CAH, including lipoid CAH caused by an abnormality in the steroidogenic acute regulatory (StAR) protein).

• Adrenal hypoplasia congenita (AHC).

• Adrenoleucodystrophy (ALD).

Secondary adrenal failure

• Adrenal suppression following steroid therapy.

• Adrenocorticotrophic hormone (ACTH) deficiency (see Chapter 7).

• ACTH resistance (familial glucocorticoid deficiency or FGD).

• Antenatal steroids administered to the mother.

• Maternal Cushing's disease/syndrome.

• Postnatal steroid therapy.

Investigations

Immediate

• Three random blood cortisol measurements (timing is not important) to look for low cortisol levels. (Plasma cortisol is difficult to interpret on a single sample because of the pulsatile nature of cortisol secretion, therefore taking 2–3 random samples makes it less likely that all will fall at a nadir. Cortisol may also be easier to interpret in the first week of life when cortisol levels are higher.)

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