02/12/2025
The main types of acne are non-inflammatory (whiteheads and blackheads) and inflammatory (papules, pustules, nodules, and cysts). Whiteheads are blocked pores closed by a layer of skin, while blackheads are open pores with a dark-colored clog. Inflammatory types include red, sore papules; pus-filled pustules; deep, hard lumps called nodules; and large, painful pus-filled cysts.
Non-inflammatory acne
Whiteheads: Also called closed comedones, these are small bumps that form when a hair follicle is completely clogged.
Blackheads: Also called open comedones, these are clogged pores that are open at the surface. The dark color is not from dirt, but from the follicle's inner lining producing a pigment.
Inflammatory acne
Papules: Small, red, and tender bumps that form when oil, dead skin cells, and bacteria cause inflammation.
Pustules: Similar to papules, but they have a white or yellow center filled with pus.
Nodules: Large, solid, and painful lumps that develop deep beneath the skin's surface when the follicle becomes severely clogged and inflamed.
