Acne: Types and Causes

Acne manifests itself in areas where there are large populations of sebaceous glands (e.g., on the face, chest and back) and occurs when the skin pores get blocked and the sebum or oil excreted by the sebaceous glands get stuck inside, thereby providing a breeding place for infection-forming bacteria.

The types of acne are:

1. Non-inflammatory – the manifestations of this acne type are whiteheads (closed comedo), which occurs when the follicle that gets plugged remains below the surface of the skin; and blackheads (open comedo) which are essentially whiteheads that emerge on the surface of the skin. You can tell the difference between the two by its color: Whiteheads appear as small, whitish-colored bumps on the skin, while blackheads are dark due to a buildup in melanin.

2. Inflammatory – the manifestations of this acne type can be as mild as a small yet firm bump in the skin that is pinkish in color (called a papule), to a slightly inflamed bump with traces of pus (called a pustule), to a large, pus-filled bump lodged deeply in the skin (called a nodule or cyst). All three manifestations are normally referred to as “pimples”.

Causes of Acne

There is not one single cause of acne; it is rather the simultaneous combination of several factors that cause of acne, including:

1. Excess production of sebum – At normal levels, sebum is beneficial to the skin because it helps keep it soft and pliable. In excessive volume, however, the sebum becomes the bed upon which bacteria can grow and contribute to the occurrence of acne.

2. High hormone levels – A large proportion of acne sufferers belong to the teenage age levels because it is at this point wherein they experience major physiological changes due to an increase in their androgen hormone levels, which enlarge the sebaceous glands. Acne occurs when the androgens over stimulate these glands, resulting to abnormal enlargements which, in combination with other factors, causes acne.

3. Excess bacterial population – In the skin’s natural sebum maintenance system is a bacterium called Propionibacterium acnes. At normal levels, this bacterium is actually beneficial to the skin. However, when a follicle’s opening narrows and eventually closes due, e.g., to follicle fallout, the bacterium’s population increases abnormally which, in turn, causes inflammation of the follicle, resulting then to acne.

4. Follicle fallout – Under normal conditions, the follicle is able to efficiently expel dead skin cells consistently with their shedding rate. However, when the sebaceous glands are abnormally enlarged, the shedding occurs at a rate faster than they can be expelled which in combination with the plugging of the follicle due to excess sebum production, causes acne because the skin is unable to effectively undertake its natural renewal process.

5. Anti-bacterial response – The body’s natural defense against unwanted bacteria is to bombard them with white blood cells in a process called chemotaxis. This process causes the inflammation and reddening of pimples (a form of acne), which can be quite an uncomfortable experience.