Some pimples pop up overnight with little to no warning. Others make their arrival known long before they ever come to the surface by causing a painful lump. The latter is typically a big pimple ...

“To be clear, you can have just purely cystic acne; that's a thing that exists,” says Dr. Shaikh. Hidradenitis suppurativa, in contrast, presents mostly as nodules and cysts under the skin.

Dealing with skin conditions like acne or psoriasis can be hard enough when you know what ... “You might be like, ‘Oh, I had this thing under my arm for a few weeks, like three years ago ...