Normal skin has an acidic surface with a pH of 5.5 to 7.0, which acts as a buffer against alkaline substances and also against acidic substances with a pH in the range of 4.2 to 6.0 to prevent damage to the body by some acidic and alkaline substances. There is still a lipid film on the surface of the skin, bathing with soap can neutralise the acidic protective film on the surface of the skin and remove the lipid film, thus leading to dry skin and thus causing itching.
Frequent bathing should be avoided and overly hot water should be avoided, while attention should be paid to enhancing skin moisturisation, such as applying body lotion after bathing to relieve itching and other discomforts to some extent.