Prolonged use of topical corticosteroids to large or extensive areas, especially with occlusive dressing, may lead to systemic side-effects, which result from excessive action on electrolyte balance, excessive action on other aspects of metabolism including gluconeogenesis, the action on tissue repair and healing, and an inhibitory effect on the secretion of corticotrophin by the anterior lobe of the pituitary gland. Disturbance of electrolyte balance is manifested in the retention of sodium and water, with oedema and hypertension, and in the increased excretion of potassium with the possibility of hypokalaemic alkalosis. Other excessive metabolic effects lead to mobilisation of calcium and phosphorus, with osteoporosis and spontaneous fractures, nitrogen depletion, and hyperglycaemia with precipitation of the diabetic state. Patients may be more susceptible to infections including tuberculosis and viral infections. Large doses of corticosteroids may also produce Cushingoid symptoms typical of hyperactivity of the adrenal cortex, with moon-face, sometimes with hirsutism, buffalo hump, flushing, increased bruising, striae, and acne, and sometimes leading to a fully developed Cushing's syndrome. If administration is discontinued these symptoms are usually reversed, but sudden cessation is dangerous.
Treatment for Overdosage: Treatment of systemic side-effects due to prolonged use of hydrocortisone or use under occlusive dressings over large areas are symptomatic, with the drug slowly withdrawn.