Addison’s Disease: Clinical Significance Of Its Diagnosis, Course, Prognosis And Management
Sisters With Addison's Disease
President John F Kennedy Had Addison's Disease
Diagnosis And Prognosis
Addison’s disease should be suspected clinically and confirmed by investigations. Chronic malnutrition, malabsorption states, megaloblastic anemia, tuberculosis, disseminated malignancy, vagabond’s disease, and psychiatric disorders should be considered in the differential diagnosis. Vagabond’s disease (Vagrant’s disease, vagavondia) used to be seen among beggars and uncared adolescents belonging to the lower socioeconomic groups. Pigmentation and excoriations develop in them due to pediculosis and constant scratching. Secondary hypoadrenalcorticism is part of hypopituitarism.
Course And Prognosis
Severe Addison’s disease is fatal if untreated. Death is caused by adrenal crisis occurring during periods of stress. Severe hyponatremia, shock, hypoglycemia or toxic reactions to drugs like morphine are common in them and these may prove fatal.
The prognosis has been completely changed with modern therapy. Apparent clinical and biochemical normalcy can be restored with adequate hormonal supplementation and fairly normal life with normal lifespan can be ensured.
Management Of Addison's Disease
This aim of therapy is to replace glucocorticoids and mineralocorticoids for life, with increase in dosage during periods of stress. Initially, hydrocortisone is given in a dose of 25-100 mg/day, the exact requirement is determined based on clinical and biochemical parameters. The optimum dosage required to keep the patient symptom-free with normal blood glucose and electrolyte levels is determined. A more objective method is to assess by the plasma cortisol levels after the administration of cortisol and adjusting the dose so as to give a peak morning level of 700- 800 nmols/liters and an evening level of 165 nmols/liter. The final dose has to be arrived at by trial and error since absorption and metabolism affect the drug response. Once a state of equilibrium is reached, long-term maintenance is by giving any one of the more potent preparations such as prednisolone, betamethasone or dexamethasone. Timing of the dosage is adjusted to coincide with the normal diurnal variations, i.e. the equivalent of 20 mg cortisol at breakfast and 10 mg at about 6 p.m. Peak serum levels are obtained 30- 60 minutes after oral administration and the action lasts for 6 to 8 hours.
Mineralocorticoids: In all cases with moderate or severe deficiency, mineralocorticoids have to be supplemented. Fluodrocortisone is the most potent preparation in this class and it is given in a dose of 0.05- 0.15 mg as a morning dose. Adequacy of therapy is assessed by the restoration of normal blood pressure and serum electrolytes. Side effects of overdose include hypertension, edema and hypokalemic alkalosis.
Fluodrocortisone is not freely available in developing countries such as Nigeria, Ghana, India and a large part of the South American region. Deoxycorticosterone acetate (DOCA) 2-5 mg given as intramuscular injection is a less effective, but useful substitute. Deoxycorticosterone trimethyle acetate has a longer action and an injection of 25 mg serves for 3- 4 weeks. In mild cases, simple supplementation of 8- 10g of salt in the diet helps in correcting hyponatremia and hypotension.
Symptomatic treatment includes prompt treatment of infections and associated abnormalities like diabetes and thyroid disorders. Therapy results in clinical and biochemical improvement and the patient becomes apparently normal. During periods of stress and other medical or surgical emergencies, the dose of corticosteroids should be stepped up to avoid the development of adrenal crisis. All subjects with hypoadrenalcorticism should carry identity cards giving details of the disease and the treatment schedule.
© 2014 Funom Theophilus Makama