Hidradenitis suppurativa can affect one or several areas of the body. Signs and symptoms of the condition include: 
Blackheads. Blackheads appear in small pitted areas of skin, often appearing in pairs.
Painful pea-sized lumps. The condition usually starts with a single, painful lump under the skin that persists for weeks or months. More bumps may form later, usually in areas where you have more sweat and oil glands or where the skin rubs together, such as the armpits, groin, buttocks and breasts.
Leaking bumps or sores. Some bumps or sores get bigger, break open and drain pus with an odor.
Tunnels. Over time, tunnels might form under the skin, connecting the lumps. These wounds heal very slowly, if at all, and drain blood and pus.
 Some people with this condition experience only mild symptoms. The course of the disease is highly variable. Excess weight and being a smoker are associated with worse symptoms, but even people who are thin and don't smoke can experience severe disease.