Moisturizers: what they are and how they work.

Moisturizers are widely used in various dermatologic and cosmetic skin therapies. Different classes of moisturizers are based on their mechanism of action, including occlusives, humectants, emollients and protein rejuvenators. Commercially available moisturizers often utilize components of each of these classes to provide their beneficial effect. Dry skin (xerosis) is the major indication of use. Others include atopic dermatitis, irritant contact dermatitis, ichthyosis, and dermatoheliosis. Although generally efficacious, moisturizers can cause a number of unwanted side-effects, including occlusive folliculitis, irritation, allergic contact dermatitis and contact urticaria.