Pharmacokinetics of topical hydrocortisone at plasma level after applications once or twice daily in patients with widespread dermatitis.

Percutaneous absorption of hydrocortisone was measured by determining plasma cortisol during dexamethasone suppression in 26 patients with widespread atopic dermatitis. The first and second days of treatment with applications of 1% hydrocortisone cream twice daily were studied separately in two groups of six patients. Plasma cortisol levels rose after the first two applications, reaching a maximum in 24 h. The levels then began to fall, indicating possible restoration of the skin barrier. In two other groups of seven patients, the second application was made with a cream base alone. Two types of cream base were studied, one with 60% water and the other with 30% water. With the base containing 30% water, a brief increment was seen after 2 h. On the basis of this pharmacokinetic study, treatment of acute dermatitis could be intensified by applying hydrocortisone cream twice a day on the first day, but from the second day onward one application a day seems to be sufficient.