Extensive bathing aggravates dry skin and hot baths cause vasodilation, which further promotes itching. Many soaps are salts of fatty acids with an alkali base. Soap is a degreaser and can also irritate skin. Older adults or individuals with dry skin should limit use of soaps to those areas with apocrine glands. Plain water should suffice for other skin surfaces.
Mild soaps have less soap or detergent content.
Superfatted soaps deposit a film of oil on the skin surface, but there is no proof that they are less drying than other soaps and they may be more expensive. Tepid baths have an antipruritic effect, possibly resulting from capillary vasoconstriction. The bath should be limited to a half hour every day or every two days. Oil can be added to the water at the end of the bath or applied to the skin before towel drying. Environment Heat increases cutaneous blood flow and may enhance itching.