Superficial Acne:
1st degree: black and white spots.
2nd degree: papules and pustules.
Deep Acne:
3rd degree: pustules and nodules.
4th degree: nodules and cysts.

How does acne develop?
Sometimes hair, tallow and skin cells get together and form a plug in the pore. The bacterium that is on the pore causes swelling. It is originated during puberty. Is more severe in men than in women.