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.
Sebum is an oily substance secreted by the sebaceous glands in mammalian skin. Its main purpose is to make the skin and hair waterproof and to protect them from drying out. An excess of sebum, however, can make the skin or hair oily, and it can begin to smell when broken down by bacteria outside the body.