Adrenal insufficiency (AI) occurs when the adrenal glands are unable to produce normal amounts of hormone, primarily cortisol but sometimes aldosterone as well. The production of cortisol is under the control of a hormone called ACTH which is released from the pituitary gland, therefore AI may be caused by either dysfunction of the adrenal glands (primary adrenal insufficiency), or dysfunction of the pituitary gland or hypothalamus (secondary adrenal insufficiency).
Cortisol plays an important part in the function of many tissues in the body. In times of stress it is essential to maintain blood pressure and to increase circulating glucose in the blood.
The degree of cortisol primary deficiency is variable and may result in no cortisol production at all or a decreased production which may provide insufficient reserve under stress conditions. For this reason some people need to take cortisol replacement every day and others may only need to take it for illnesses, surgery or other stress conditions. Insufficiency of aldosterone, also produced by the adrenal glands and important for the maintenance of normal blood pressure, only occurs in some cases of AI.
Primary (from the adrenal gland)
- Autoimmune (Addison’s disease)
- Congenital adrenal hyperplasia, congenital adrenal hypoplasia
- Infection – septicaemia secondary to severe bacterial infection, tuberculosis, fungal infections
- Adrenal haemorrhage
- Bilateral adrenalectomy (removal of the adrenal glands) treatment for adenoma or carcinoma of the adrenal gland
- Genetic (rare)
- Idiopathic (cause not yet identified)
Secondary (from the pituitary or hypothalamus)
- Congenital hypopituitarism eg. genetic, septo-optic dysplasia, idiopathic
- Pituitary/hypothalamic tumours eg. Craniopharyngioma, astrocytoma, glioma
- Withdrawal from glucocorticoid therapy eg. high doses of prednisolone for asthma
- Trauma – head injury
Adrenal insufficiency may present as acute or chronic, both resulting from a lack of cortisol.
Whilst cortisol is often referred to as the ‘stress hormone’ it is also important for the normal function of the body in everyday life. In those who do not present with acute AI (adrenal crisis), AI onset may be slow and may mimic depression or chronic fatigue syndrome.
Acute AI, usually, but not always, occurs in response to major physical stress such as illness or trauma.
Signs and symptoms of acute adrenal insufficiency
- Nausea and /or vomiting
- Extreme weakness
- Low blood glucose level
- Shock (low blood pressure, rapid heart rate, loss of consciousness
- Mental confusion
- Extreme drowsines
- Severe headache
Signs and symptoms of chronic adrenal insufficiency
- Loss of appetite, weight loss
- Nausea, vomiting
- Recurrent abdominal pain
- Diarrhoea, it may mimic a gastro illness
- Muscle weakness
- Increased skin pigmentation, particularly at the site of scars, pressure points like the elbows under the arms and gums
- Low blood pressure – postural hypotension
- mental state, it may mimic a psychiatric disorder
In times of stress extra cortisol is normally secreted to enable the body to mount a ‘stress response’. Under stress situations cortisol is necessary to prevent a possible life threatening drop in blood pressure and to increase the concentration of glucose for use by essential tissues such as the brain and red blood cells.
In adrenal insufficiency the body cannot make this extra cortisol and to prevent collapse and possible death, extra hydrocortisone must be taken by mouth or by intramuscular or intravenous injection.
Stress situations that require extra hydrocortisone:
- Severe infection with fever
- Gastroenteritis with vomiting illness and / or diarrhoea
- Dental surgery
- Severe trauma – car accident, sports accident resulting in serious injury or broken bone
Treatment of AI will depend on the diagnosis. Replacement of cortisol is achieved with a medication called hydrocortisone, given 2 – 3 times a day. Prednisolone or Dexamethasone are sometimes prescribed for adult patients but they are rarely used in children because they are more potent and can effect growth. Individuals with AI may only require hydrocortisone during times of illness.
The daily dose of hydrocortisone is carefully adjusted based on the child’s weight and height so as not to give above what the body requires as maintenance therapy. This is to avoid unwanted side effects of excess steroid medication such as growth suppression, obesity, low bone density, stretch marks on the skin and high blood pressure.
During times of illness, injury or other physical stress, extra hydrocortisone is needed to prevent an adrenal crisis. Hydrocortisone can be prescribed prior to any procedure, it is usually given intra muscularly or intravenously. Outside of these predictable circumstances the patient, or, in the case of a child, a parent or carer must make the decision to increase oral hydrocortisone, give intramuscular hydrocortisone, and / or seek medical advice.
At the Women’s and Children’s Hospital an Adrenal Crisis Action Plan outlining when and how to give extra hydrocortisone is given to the parents of any child with adrenal insufficiency. Some parents are taught now to give intramuscular hydrocortisone in the case of an emergency, especially those with younger children who become unwell more rapidly.
Hospital case notes are flagged so that appropriate emergency care may be given on admission. A MedicAlert bracelet is essential so that any other hospital, medical practice or paramedics may gain access to information that will help them to give appropriate emergency care, i.e. intra muscular or intravenous hydrocortisone.
Below are the guidelines the Department of Diabetes and Endocrinology recommend for their children:
ILLNESS OR FEVER
- Low grade fever (up to 38.50) and appears well – no additional tablets
- Low grade fever (up to 38.50) but visibly unwell – triple dose and observe
- High fever (over 38.50) triple dose and seek medical advice
VOMITING OR DIARRHOEA
- Mild – 1 or 2 episodes – triple dose
- Further vomiting and /or diarrhoea?
Yes – seek medical advice and/or give hydrocortisone injection
No – give sugar and fluids, subsequent doses as normal
- Should they become sleepy or drowsy from any illness or injury URGENT hydrocortisone injection is required. Take your child to the nearest hospital for further assessment and treatment without delay.
MAJOR ILLNESS, INJURY OR SURGERY
- When extra hydrocortisone is unable to be given by mouth and /or the child is extremely unwell, an emergency hydrocortisone injection is required.
- Give the injection if you have been taught how to use it.
- Take your child to the nearest hospital without delay for further assessment and treatment
Remember, an unnecessary dose of hydrocortisone cannot do any harm when given as a one off dose. If in doubt it is always safer to give extra hydrocortisone than wait until your child becomes seriously ill.
Adrenal insufficiency is a rare disease and not every hospital or doctor will be familiar with it. You may have to take responsibility and ask for an injection of hydrocortisone to be given.