What is the purpose of a skin patch test?

The purpose of a skin patch test is to check for allergic reactions. This test helps identify whether a person is sensitive or allergic to specific substances, such as ingredients found in cosmetics, hair dyes, or other topical products. By applying a small amount of the substance to the skin and observing any reactions over a specified period, practitioners can determine if that product may cause irritation or allergies in the individual.

The other choices do not align with the primary function of a patch test. Determining skin tone, evaluating skin texture, and assessing hydration levels involve different techniques and assessments that do not specifically address allergic reactions. Therefore, the focus of a patch test on identifying allergies makes it a critical procedure for ensuring the safety and comfort of clients in cosmetology practices.