Abstract
Objective: To evaluate the skin changes of the neck of normal individuals after repeated applications of moderate-strength corticosteroid or tracrolimus ointment for 3 weeks by use of noninvasive biophysical measurements. Methods: A 0.12% betamethasone-17-valerate ointment or a 0.1% tacrolimus ointment was applied to the right side of the neck of 8 adult volunteers twice daily for 3 weeks together with control petrolatum applied to the left side of the neck for comparison. Biophysical skin measurements were performed on the neck skin before, 1 and 3 weeks after the start of the treatment and 1 week after the cessation of the treatment. Results: A decrease in hygroscopicity and water-holding capacity of the stratum corneum (SC) when evaluated with the in vivo water sorption-desorption test was found on the corticosteroid-ointment-treated side after 3 weeks of the treatment as compared with the petrolatum-treated side. The erythematous reaction to a topically applied 0.1% aqueous solution of methyl nicotinate, a vasodilator, appeared more slowly on the corticosteroid-ointment-treated skin than on the control skin. No such changes were observed on the skin treated with 0.1% tacrolimus ointment. Conclusion: Tacrolimus appears to cause few if any functional changes in the SC of healthy human skin because of its poor permeability into skin with an intact barrier function.