Hidradenitis suppurativa can affect one spot or multiple areas of the body. Signs and symptoms of hidradenitis suppurativa include: 1  Blackheads. Small pitted areas of skin containing blackheads â often appearing in pairs or a double-barreled pattern â are a common feature.  Red, tender bumps. These bumps often enlarge, break open and drain pus.
Sebum is an oily substance that's secreted by sebaceous glands to keep skin moisturized. Too much leads to oily skin and too little leads to dry skin. Sebum is an oily substance that's secreted by sebaceous glands to keep skin moisturized.
Interestingly, sebaceous glands are also found in parts of the skin that usually lack hair. They are found on a personâs eyelids, nose, and nipples. They are also found on parts of the genitals that are entirely devoid of hair. In these places, the sebum doesnât travel through hair ducts.