The first warning sign of hidradenitis suppurativa (HS) is sometimes just a single, painful bump that gets inflamed. It can last for several days or months. There can be repeated outbreaks of a single bump in the same location or the same general area.
The bumps can turn into pockets of pus under the skin that leak and have a bad smell. They can also be itchy. You can get them in one place or several areas at once.
If the bumps are deep, they can turn into scars when they heal. Some people get tunnels under their skin, called sinus tracts, which connect different areas of HS outbreaks.
The bumps and leaky pockets can go away and come back. In severe cases, they don't fully heal.