**6. Conclusion**

Epidermal barrier dysfunction is observed in a variety of skin diseases, such as atopic dermatitis, psoriasis, and contact dermatitis, and barrier disruption induces an inflammatory response that might aggravate dermatitis (Grice 1980). On the other hand, acceleration of barrier recovery was shown to improve epidermal hyperplasia (Denda 1997)(Fuziwara 2004). Since a wide range of physical or chemical factors, as described here, influence barrier homeostasis, control or modulation of these factors is expected to open up new possibilities for the treatment of human skin diseases involving barrier abnormality.
