It Used to be Commonplace For People to Wear Pubic Wigs

There’s a name for a wig that you put on your pubic region. It’s called a “merkin”. It’s unusual now, but this was an especially common practice among prostitutes and other people who engaged in a lot of sexual activity.

It’s a good way to cover up sores from STD’s. Also, since syphilis was often treated by shaving the pubic region or treating it with mercury (which causes hair loss), the merkin served as a replacement for all that missing pubic hair.

Merkins also saw some use for the same reasons that people wear wigs, i.e. baldness or wanting have a different hair color.

Source: THE STRAIGHT DOPE