Hypoadrenalism (includes Addison's disease)

What is Hypoadrenalism?
Statistics on Hypoadrenalism
Risk Factors for Hypoadrenalism
How is Hypoadrenalism Diagnosed?
Prognosis of Hypoadrenalism
How is Hypoadrenalism Treated?
Hypoadrenalism References
Drugs/Products Associated with Hypoadrenalism

What is Hypoadrenalism?

Hypoadrenalism is a disease of the entire adrenal cortex.

Statistics on Hypoadrenalism

Primary hypoadrenalism is relatively rare, for example it is found in about 6 in every 100,000 people in the North East Thames region. Much more common is ACTH deficiency caused by the intake of cortisol-like steroids for conditions such as asthma. Cortisol is required as part of the body's response to physical stress (e.g. emergency surgery). Failure to diagnose hypoadrenalism in an ill patient may lead to collapse and death.

Risk Factors for Hypoadrenalism

Autoimmune - Associated with other autoimmune conditions. 90% of cases result from destruction of the adrenal cortex by organ specific autoantibodies.

Adrenal gland tuberculosis

Surgical removal

Haemorrhage (meningococcal or pneumococcal meningitis)

Malignant infiltration

Secondary adrenocortical failure as a result of pituitary disease.

How is Hypoadrenalism Diagnosed?

Urea and electrolytes - classically, low sodium, high potassium, raised urea. May be normal.

Blood glucose - low. May be normal

Full blood count - neutrophil leucocytosis and eosinophilia.

Radiology - evidence of TB (calcified adrenals)

Prognosis of Hypoadrenalism

With adequate replacement therapy, most people with Addison's disease are able to lead normal lives.

How is Hypoadrenalism Treated?

Lifelong steroid replacement

Hydrocortisone - usual dose is 20mg on waking and 10mg in the morning (mimics normal diurnal rhythm).

Fludrocortisone - a synthetic mineralocrticoid. Dose is adequate when there is no postural blood pressure drop and renin levels are normal.Important that steroid doses are increased in cases where there would normally be an increase in ACTH (infection,trauma, surgery). Thus the dose must be increased when they are placed in these situations.- Addisonian crisis- Hydrocortisone IV, Rapid IV fluids and 50% dextrose if hypoglycaemic.

Hypoadrenalism References

[1] Braunwald, Fauci, Kasper, Hauser, Longo, Jameson. Harrison's Principles of Internal Medicine. 15th Edition. McGraw-Hill. 2001[2] Cotran, Kumar, Collins 6th edition. Robbins Pathologic Basis of Disease. WB Saunders Company. 1999.[3] Hurst JW (Editor-in-chief). Medicine for the practicing physician. 4th edition Appleton and Lange 1996.[4] Kumar P, Clark M. CLINICAL MEDICINE. WB Saunders 2002 Pg 427-430.[5] Longmore M, Wilkinson I, Torok E. OXFORD HANDBOOK OF CLINICAL MEDICINE. Oxford Universtiy Press. 2001