Infrared spectroscopic measurements of hydration of the stratum corneum before and after stripping the skin five and ten times with scotch tape are reported. Investigations on 64 healthy persons show that for individuals over 45 and under 15 years of age the range of the measurement values is strikingly larger than for persons in the age group 15 - 45 years of age. A small, but not significant reduction in the measurement values is found in females as compared to males. A comparison of the clinically unaffected skin of atopic dermatitis patients with the skin of normal persons points to an increase in the hydration of the stratum corneum of atopic dermatitis patients, which is especially evident in patients who show clinical evidence of "dry" and rough skin.