Addison’s Disease

What is this?

This is a condition which causes the adrenal glands to fail.It is called after the doctor who first described the disease namely a Dr Addison

The disease often comes on slowly. The patient often describes tiredness or generally feels unwell. Weakness is common, there is a loss of appetite with weight loss. A characteristic feature seen in 95% of patients is pigmentation. This is often most marked over areas exposed to the sun but never fades even in the winter. The pigmentation however can be found in areas not exposed to the sun such as inside the mouth, along natural skin creases (e.g. palm of hand creases), also where there is rubbing by garments such as bra straps or the elastic band of knickers and on scars and around nipples. Some 30% develop abdominal pain, others constipation (20%), while others have diarrhoea (20%). Often another illness may show up the condition for the patient has great difficulty recovering from minor injury, operations or illness.

Women may suffer loss of body hair with irregular or lack of menstrual periods. Often the patient may complain of light headness, weakness, sweating and blurred vision if without food due to low blood glucose (hypoglycaemia).Often the blood pressure is low and falls when the patient stands up often to unrecordable levels causing the patient to feel faint.

Rarely adrenal crises can occur. Vomiting usually occurs first with abdominal pain, diarrhoea, dehydration and complete patient collapse requiring admission to hospital as an apparent acute surgical emergency. The initial impression is that of gut obstruction.The patient rapidly responds to intravenous salt solution for in Addison’s the adrenals fail to produce the hormone aldosterone which in a healthy person retains salt within the body. In a crisis so much salt is lost that the blood pressure collapses.

The doctor will measure the blood cortisol which is a hormone produced by the adrenals. The adrenals are best tested for their activity by performing a short synacthen test. In this the patient is given an injection of the hormone ACTH (called synacthen) which in healthy people switches on the adrenal to produce cortisol. In Addison’s the adrenals do not respond or do so sluggishly. The hormone ACTH is naturally produced by the body from the head hormone gland called the pituitary. In patients with Addison’s the level of blood ACTH will be very high as the pituitary over-produces to try and switch on the adrenals that have failed. High blood ACTH and low cortisol levels are characteristic of Addison’s. This condition also causes the blood potassium to be high and blood sodium low due to lack of a second adrenal hormone called aldosterone.

There are a number of causes.

• Most (70%) are due to the body itself self destroying the adrenals called ‘auto-immune endocrine disease’. This appears to be due to the body producing proteins called antibodies which destroy or switch off the adrenals. This is an inherited condition often involving other members of your family possibly in other ways. In autoimmune endocrine disease other hormone glands may be involved such as thyroid causing an underactive or even overactive thyroid, diabetes mellitus, premature menopause (premature ovarian failure), pernicious anaemia, loss of scalp hair or total body hair (alopecia areata), underactive pituitary gland, loss of pimentation in patches (vitiligo) and rarely low blood calcium due to failure of the parathyroid glands.The patient may already have developed one or more of these conditions or may have family members with these conditions. The specialist will test for these.Sometimes the antibodies destroying the adrenals can be detected in the blood but often may not be present if the Addison’s has gone on for some time.
• Tuberculosis can cause the adrenals to fail. The specialist will test for this with a Chest Xray to detect TB in the lung, plain abdominal Xray to detect calcification of the adrenals, and specific tests for TB. Patients with HIV or AIDS are particularly susceptible to TB causing adrenal failure.
• Adrenal destruction due to other diseases such as spread of cancer from elsewhere (such as the lung, breast, lymphoma), haemorrhage, thrombosis, rare fungal infections, even viruses (cytomegalic virus) and rare conditions such as haemochromatosis ( disease causing iron overload), amyloid and sarcoidosis, can be causes. The specialist will also check these out.

Often this requires the patient to enter hospital where intravenous fluids are given to replenish the body’s salt content which is depleted in Addison’s. Steroid are essential comprising two types. The first is called hydrocortisone and replaces the body’s lack of cortisol. This is usually given a tablets taken twice or three times per day. If given twice per day then the specialist will often ask the patient to take twice as much in the morning as in the late afternoon so as to mimic the healthy cortisol levels which are higher in the mornings. Also the patient will be asked to take fludrocortisone to replace the adrenals other absent hormone called aldosterone. Fludrocortisone is taken in the morning.

You will be followed up regularly and lifelong by the specialist or your general practitioner. Regularly your blood pressure lying and standing will be checked and blood test of your blood sodium, potassium and occasionally renin measured. Renin is measured to assess whether your fludrocortisone is adequate.

It is essential to double the dose of hydrocortisone if you become ill from even minor illness such as a head cold. If you develop vomiting or diarrhoea then make sure you are seen by a doctor within hours even if this means coming into A+E. Do not hesitate to seek advice sooner than later. Always carry a card or Medi-alert bracelet to tell others that you have Addison’s and are on steroids.

Where can I find out more?

Why not try the website: http://www.niddk.nih.gov/health/endo/pubs/addison/addison.htm

or  http://adshg.org.uk

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Ó NHS Tayside; 2006; version 1.0

Disclaimer; no liability whatsoever is accepted for information given and all such information, especially with regard to drug usage (UK version provided), must be checked with a person’s health provider.