Problem with adding hairs in particle edit mode

I’ve got this character model that I’d like to add hair to, so I’ve added a hair particle system to it and tried styling it using Particle Edit mode. But he’s got a little bald spot on the top of his forehead here:

I’m trying to use the Add tool to add a hair there, but when I click somewhere, it ends up adding hairs in seemingly random other places on the model, like I can click on the forehead here and it adds some hairs all over the rest of the face, pretty much everywhere except where I clicked.

In the most extreme case, I clicked on the head and it added hairs on the arms. I’ve tried recalculating the normals several times but it doesn’t seem to help.

I ended up working around it by creating a separate scalp mesh and adding the hair to that instead, so problem solved i guess.