Acne Glossary

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Most of us think of pimples when we think of acne. We don't bother dividing up the different annoying spots we see on our face. But dermatologists have broken pimples into the following categories:

Comedo
An oil duct plugged up with oil, dead skin cells, and bacteria
Whitehead
A closed comedo, or a comedo with skin covering the top. It looks like a tiny, white bump.
Blackhead
An open comedo, or a comedo that does not have skin covering it. It appears black not because it contains dirt, as is commonly believed, but because the material has been exposed to oxygen.
Papule
A ruptured comedo in which there is inflammation and secondary infection. It looks like a small, hard, red bump.
Pustule
A ruptured comedo in which there is inflammation and secondary infection. In contrast to the papule, the pustule has more pus near the surface, giving it a yellowish center.
Nodule
Sometimes called a cyst. A ruptured comedo that is generally larger, deeper, and more painful than a pustule and is more likely to result in scarring. This type of lesion marks the most severe form of acne.