Percutaneous absorption of biotin in healthy subjects and in atopic dermatitis patients

The study was designed to test the ability of sequential applications of bi otin-containing ointment to increase serum biotin levels. Twenty atopic der matitis patients (mean age, 20.5 yr) and 11 healthy subjects (mean age, 25. 5 yr) volunteered to participate in this study. The diagnosis of atopic der matitis was established dermatologically. Seven grams per day of ointment c ontaining 0.3% biotin and 1-4 g per day of steroid ointment were both appli ed sequentially. The healthy subjects applied only biotin ointment. The bio tin concentration was determined microbiologically. Before biotin treatment , the average serum biotin level was significantly lower in atopic dermatit is patients than in healthy subjects. The percutaneous application of bioti n-containing ointment caused a significant increase in the serum biotin con centration in both healthy subjects (from 41.5 +/- 10.0 to 50.2 +/- 9.2 nmo l/L) and in atopic dermatitis patients (from 27.9 +/- 17.4 to 50.7 +/- 21.6 nmol/L), especially in patients whose initial level was low, and also coul d be effective in regulating the atopic allergic response involving eosinop hils. In conclusion, biotin appears to be readily absorbed through both nor mal and dermatitis-affected human skin.