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How Acne Forms

From , former About.com Guide

Updated October 28, 2007

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Acne - Pustule
How Acne Forms
A pustule is different from a pimple only because it contains white blood cells. As the immune system fights off the P. acnes infection, sometimes white blood cells (a part of the immune system) pile up creating pus in the pore. This is called a pustule. We know what parts of the immune system are involved in making pimples and pustules, but it is unclear why some lesions develop pus in them and others don't. This only matters from a scientific standpoint because, practically, pimples and pustules are treated the same way.

Medications that help at this stage include:

  • Over-the-counter benzoyl peroxide kills bacteria and helps prevent P. acnes from overgrowing.
  • Prescription tretinoin products like Retin-A, Retin-A Micro, and Avita reverse the "stickiness" of the skin cells allowing them to slough normally.
  • Over-the-counter salicylic acid 2% lotion is a beta hydroxy acid that also reverses the "stickiness" of the skin cells.
  • Prescription topical antibiotics kill the P. acnes bacteria and are often used if a person has some pustules.
  • Prescription oral antibiotics also kill the P. acnes bacteria and are often used if a person has a lot of pustules.
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