When should I consider referring a patient with suspected Addison's disease to an endocrinologist?

Consider referring a patient with suspected Addison's disease (primary adrenal insufficiency) to an endocrinologist if:

• Their 8 am to 9 am serum cortisol level is below 150 nmol/L, as this strongly suggests adrenal insufficiency and warrants specialist assessment and management initiation. If the patient is acutely unwell, urgent referral and emergency management are required.
• If the serum cortisol level is between 150 nmol/L and 300 nmol/L, the probability of adrenal insufficiency is uncertain; consider repeating the test and seek endocrinology advice or referral if levels remain in this range.
• For children and young people under 16 years, refer urgently to paediatrics or paediatric endocrinology if adrenal insufficiency is suspected, especially with cortisol levels below 150 nmol/L or if acutely unwell.
• In babies under 1 year, seek paediatric endocrinology advice for interpretation of cortisol levels measured at any time of day.
• Also consider referral if the patient has clinical features suggestive of adrenal insufficiency (e.g., unexplained hyperpigmentation, weight loss, salt craving, hypotension, hyponatraemia, hyperkalaemia, hypoglycaemia) and risk factors such as recent glucocorticoid withdrawal, use of medications affecting cortisol, or coexisting autoimmune or pituitary conditions.

Do not test or refer based on cortisol levels if the patient is currently taking oral glucocorticoids at physiological equivalent doses or above, as this can confound results.

Referral should be prompt to ensure timely diagnosis, initiation of corticosteroid replacement, and prevention of adrenal crisis.

References: NICE NG243