Blackheads

Blackheads occur when a pore is clogged by a combination of sebum and dead skin cells. The top of the pore stays open, despite the rest of it being clogged. This results in the characteristic black color seen on the surface.

Whiteheads

Whiteheads can also form when a pore gets clogged by sebum and dead skin cells. But unlike with blackheads, the top of the pore closes up. It looks like a small bump protruding from the skin.

Whiteheads are more difficult to treat because the pores are already closed. Products containing salicylic acid can be helpful. Topical retinoids give the best results for comedonal acne. Currently, adapalene (Differin) is available over the counter as a retinoid. If it does not work for you, stronger topical retinoids are available by prescription from your dermatologist.

Papules

Papules occur when the walls surrounding your pores break down from severe inflammation. This results in hard, clogged pores that are tender to the touch. The skin around these pores is usually pink.

Pustules

Pustules can also form when the walls around your pores break down. Unlike papules, pustules are filled with pus. These bumps come out from the skin and are usually red in color. They often have yellow or white heads on top.

Nodules

Nodules occur when clogged, swollen pores endure further irritation and grow larger. Unlike pustules and papules, nodules are deeper underneath the skin.

Because nodules are so deep within the skin, you can’t typically treat them at home. Prescription medication is necessary to help clear these up.

Cysts

Cysts can develop when pores are clogged by a combination of bacteria, sebum, and dead skin cells. The clogs occur deep within the skin and are further below the surface than nodules.

These large red or white bumps are often painful to the touch. Cysts are the largest form of acne, and their formation usually results from a severe infection. This type of acne is also the most likely to scar.