Which service typically does not require a patch test?

Haircuts do not require a patch test because they involve no chemical processes that could potentially cause an allergic reaction. A haircut simply involves trimming or styling the hair, which does not expose the scalp or hair to any substances that could provoke a skin reaction.

In contrast, services like hair coloring, curling treatments, and chemical straightening often involve the application of chemicals that can cause allergic reactions in some individuals. For these services, a patch test is a precautionary measure to ensure the client is not sensitive to the products being used. Therefore, it is essential to perform a patch test for those services to avoid adverse reactions, whereas a haircut remains a straightforward service that does not pose the same risk.