Addison’s disease is primarily characterized by declining secretion of steroid hormones from the adrenal glands. Primarily there are low levels of cortisol and aldosterone. Treatment is aimed at replacing these hormones with the help of medications.
Diagnosis of Addison’s disease
Addison’s disease is difficult to diagnose initially. Symptoms and presentations at initial stages and medical history may raise suspicion of the disease.
The diagnosis is confirmed using laboratory tests. The tests help to determine whether levels of cortisol are deficient and then attempts are made to establish the cause. This is followed by imaging studies to assess the state of the adrenal glands and the pituitary glands.
One of the primary diagnostic tests is the ACTH (Adrenocorticotrophic hormone) Stimulation Test. ACTH normally stimulates the secretion of cortisol in the body. For this test blood and urine levels of cortisol are measured before and after a synthetic form of ACTH are given by injection.
In a normal person after an ACTH injection there is a rise in blood and urine cortisol levels. Those with Addison’s disease or adrenal insuficiency have little or no increase in cortisol levels. To detect the severity of the insufficiency both low- and high-dose ACTH stimulation tests may be used.
Another test is the CRH (Cortisol releasing hormone) Stimulation Test. For this test synthetic CRH is injected intravenously in the patient. After injection the blood cortisol is measured at 30, 60, 90, and 120 minutes after the injection.
In patients with Addison’s disease response to CRH is high levels of ACTH and no cortisol. Those with secondary adrenal insuficiency have absent or delayed ACTH responses.
In patients with Addisonian crisis measurement of ACTH and cortisol levels and response to glucocorticoid injection is a diagnostic marker of Addison’s disease. In addition there may be low blood sodium, low blood glucose, and high blood potassium. After controlling the crisis ACTH stimulation test may be performed to confirm the diagnosis.
Treatment of Addison’s disease
In patients with an underlying cause of Addison’s disease like tuberculosis, the cause needs to be treated. Tuberculosis is treated with anti-tuberculosis medication over a period of at least six months. Those with a viral or fungal infection causing adrenal damage are treated with appropriate drugs.
Patients with Addison’s disease need to be treated to hormonal replacement for the low levels of cortisol. Supplementation of the hormones can replace the lost hormones and ensure a normal life.
For patients with Addison’s disease corticosteroids are prescribed as part of steroid replacement therapy. This therapy is usually for life among those with primary adrenal insufficiency. Corticosteroids are prescribed as oral drugs usually twice a day.
For cortisol replacement synthetic glucocorticoids like hydrocortisone is used. Other alternatives include dexamethasone and prednisolone. Aldosterone replacement is achieved using an oral mineralocorticoid called fludrocortisone and ludrocortisone acetate.
Precautions to prevent adrenal or Addisonian crisis
Certain steps may be taken to prevent attacks of Addisonian crisis. These include:-
Following up regular appointments with the Endocrinologist every 6 to 12 months.
Not missing any medication and collecting repeat prescriptions. There should be spare medication as necessary especially while travelling.
Medication needs to be taken at the same time each day
Medical alert bracelets or necklace can help identify a patient with Addison’s disease. This can help identify patients who meet an accident need cortisol to cope with the added stress, failing which they may develop Addisonian crisis.
Medications (corticosteroids) need to be increased and adjusted in stressful conditions like an illness or infection with fever, before an operation or medical procedure, before strenouous exercise, before a dental procedure and after an accident. This helps the body cope with the additional stress.
Treatment of Addisonian crisis
There is usually a symptomatic management that needs to be administered urgently. Initially intravenous fluids are given to maintain the fluid balance, blood pressure and prevent hypovolemic shock and collapse. There is supplementation of sodium and sugars like glucose and dextrose in the fluids.
Hydrocortisone injection is given to manage the crisis. Treatment of the illness or infection that has precipitated the crisis is also important to treat Addisonian crisis.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)