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.
Sebaceous glands are your oil glands and are found in the dermal  layer of the skin. They are located everywhere on the human body,  excluding hands and palms. Sebaceous glaâ¦nds are more common around  the face and the head.    Sebaceous Glands can be found in all parts of the skin in the human body except soles and palms.