What Causes Acne

The main cause of acne is not known yet, but the following factors are considered important: When the skin surface and its pores are blocked, the pores are described as being occluded. Factors that may cause occlusion include certain cosmetics, oils, greases, and hairsprays. Hats, helmets and pads used in sports may also contribute to this problem as can humidity, sweating and the prolonged effect of contact with damp clothing...

All acne is a disorder of the Pilosebaceous unit, made up of sebaceous gland, hair follicle, and a hair. These units can be located everywhere on the body except on the palms, top of the feet soles, and the lower lip. The number of Pilosebaceous units is greatest on the face, upper neck, and chest. Sebaceous glands produce a substance called sebum, Sebum is a substance produce by Sebaceous gland, which is responsible for keeping the skin and hair moisturized. During adolescence, sebaceous glands enlarge and more sebum is produced under the influence of hormones, also called androgens. After the age of 20, sebum production begins to decrease.

Acne & Bacteria
A bacteria, called Propionibacterium acnes, is a normal inhabitant of the skin. This bacteria uses sebum as a nutrient for growth, therefore increases in follicles during puberty. People with acne have more Propionibacterium acnes in their follicles than people without acne. When this bacterium is present in the skin, it attracts white blood cells to the follicle. These white blood cells attracted to the follicle produce an enzyme that damages the wall of the follicle, allowing the contents of the follicle to enter the dermis. This system results to an inflammatory response seen as papules (red bumps), pustules and nodules. These bacteria also cause the production of free fatty acids, which are irritants, increasing the inflammatory process in the follicle.

Normal Follicles
Sebum, which produce of the sebaceous gland combines with cells being sloughed off within the hair follicle and "fills up" the hair follicle. When the hair follicle is "full", the sebum spreads over the skin surface and an oily appearance is seen on the skin surface. When this process works correctly, the skin is moisturized and remains healthy.

Obstructed Follicles
When the sebum is trapped in the hair follicle it causes a lot of problem. The reasons behind this are not yet clear, some hair follicles become obstructed. The sebum is produced but they get trapped on the way out, and the cells that are normally sloughed off become "sticky", plugging up the follicle. The process by which follicles is obstructed is called comedogenesis. These obstructions cause the follicle to form a type of acne called comedones, also known as blackheads and whiteheads.