ABSTRACT

Dry skin is commonly observed in various dermatoses such as atopic dermatitis, psoriasis, ichthyosis, and xenile xerosis [1]. Dermatitis induced by environmental factors such as exposure to a detergent, organic solvent, low humidity, and UV irradiation also show skin surface dryness [1]. Dry, scaly skin is characterized by a decrease in the water-retention capacity of the stratum corneum [2] with water content decreased to less than 10%. Hyperkeratosis, abnormal scaling, and epidermal hyperplasia are usually observed in dry skin [3]. Patients often suffer from itching. In some cases, the skin barrier function of the stratum corneum is decreased and trans-epidermal water loss (TEWL) is increased because of abnormality in barrier homeostasis [3]. In modern life, various environmental factors might induce the xerosis. For example, dry scaly skin has been reported among industrial painters in Japan [4]. People working in the industry also had irritated skin without any specific reason. Household detergents have also been reported to induce dry skin in Japan. Imabayashi reported [5] that 26.7% of the 1861 female university students in her survey had suffered from impaired skin due to the use of household detergents, and 74.6% of the subjects who claimed of having skin problems showed dry scaly skin. There were some seasonal changes in the occur-

rence of dry skin induced by detergents. A previous study suggested that environmental dryness itself induces xerotic skin [6].