Final answer:
A sebaceous cyst is also known as acne when it involves infected sebaceous glands. Cysts form when hair follicles clog with shed skin cells and sebum, leading to comedones like whiteheads and blackheads. Bacterial infection can cause inflammation and scarring.
Step-by-step explanation:
A sebaceous cyst, which may range in size from a pea to an orange, is also known as acne when associated with infected sebaceous glands. The formation of these cysts occurs when hair follicles become clogged with shed skin cells and sebum, an oily substance produced by the sebaceous glands to waterproof the skin and hair. This can lead to the development of comedones—whiteheads and blackheads—which are non-inflammatory lesions. When exposed to the air, the lipids in blackheads oxidize and turn black. Infection by acne-causing bacteria such as Propionibacterium and Staphylococcus can result in inflammation and potentially lead to redness and scarring.