November 12, 2007
Bacteria And Acne
The microcomedo may develop into, and remain, a comedo. But sometimes it becomes an inflammatory lesion. Inflammation is a reaction of the skin to disease or injury; in the case of acne, the inflammation is a reaction to the bacteria known as Propioni-bacterium acnes. Signs of an inflammatory lesion include swelling, redness, heat, and sometimes pain. The presence of these bacteria does not mean that poor hygiene is a cause of your acne.
Here's a list of common inflammatory acne lesions:
- Papule: A small, firm red bump, commonly referred to as a pimple or zit. It's made up of inflammatory blood cells and doesn't contain obvious pus.
- Pustule: A papule that contains pus, a whitish, goopy substance that's really just a bunch of white blood cells. Pustules are also known as "pus pimples."
- Nodule: A large and often tender, lumpy, inflamed, pus-filled papule or pustule that's lodged more deeply in the skin. The term cyst is often used interchangeably to mean "nodule" because of the resemblance of a nodular acne lesion to a cyst.
One other common acne lesion is sometimes formed late in the life cycle of a lesion from the remains of an inflammatory lesion:
- Macule: A macule is a flat red, purple, or brown spot that forms where a papule or pustule used to be. A macule remains for a while after an acne lesion has healed or is in the process of healing.






