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.
by perspiration (sweat glands cause water to be evaporated from the surface of your skin, cooling your body). Excretion. Your body excretes substances through the skin: sebum (skin oil), which helps to make your skin water repellent and maintain its smooth texture, and also defends your body against fungus and bacteria water, salts and several other substances, through the process of perspiration.