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.
There is no real difference, it is just a matter of quantity. If you have a few, they are usually referred to as âspotsâ, âpimplesâ or âzitsâ. But if you have quite a lot of whiteheads, blackheads or angry-looking inflamed spots, it is referred to as acne.he skin contains millions of sebaceous glands that secrete a grease (sebum), through the skin pores onto the surface of the skin. Normally sebum simply helps to keep the skin healthy. A spot forms when a pore becomes blocked by a plug of dead skin cells mixed with sebum.