What Is Acne

Acne is a inflammatory disease of the skin caused by changes in the pilosebaceous units (hair follicle and its associated sebaceous gland - oil glands.) The pores in your skin connect to these oil glands under the skin. These glands make an oily substance called sebum that is used to carry dead skin cells to the surface of the skin.

Acne occurs when the oil glands produce excessive secretion of oils that then combines with the dead skin cells to block the hair follicles. In other instances, acne can be caused by a faulty keritinization process in the skin leading to abnormal shedding of skin lining the pores. Oil secretions then build up beneath the blocked pore which provides a perfect environment for the skin bacteria Propionibacterium acnes to begin multiplying uncontrolled. In response to this infection, the skin becomes inflamed, producing the visible lesions called pimples. Typically the face, chest, back, shoulders, and upper arms are especially affected. Acne is not a serious health threat but it can cause scarring.

Acne causes many types of skin lesions (pimples):

Whiteheads - Pimples that stay under the surface of the skin.
Blackheads - Pimples that have risen to the skin's surface and look black. The color is not caused by dirt.
Papules - Small pink bumps that can be tender.
Pustules - Pimples that are red at the bottom and white with pus at the top.
Nodules - Large, painful, solid pimples that are deep within the skin.
Cysts - Deep, painful, pus-filled pimples that can cause scars.