Acne is a disease usually associated with teenagers. Three out of four teenagers end up with this disease.

Acne is a skin disorder which is caused by plugged pores on the skin. Acne lesions arise through pilosebaceous units, which are made of sebaceous glands and hair follicles in the middle layer of skin called the dermis. Pilosebaceous units are found all over the body except in the palms of hands and the bottoms of feet. That’s why we do not have body hair or oil glands in these places, and thus no acne. Pilosebaceous units are the densest on the face, upper neck and the chest.

The first and foremost reason for acne development is the overproduction of sebum, which clogs the pilosebaceous canal. Sebum production is affected by male hormones called androgens. That’s why any fluctuation in hormonal balance or stimulation of male hormones due to various reasons always leads to acne.

With excess sebum production, the cell lining of the follicle wall also starts to overproduce (Ductal Hypercornification). These dead cells along with the extra amount of sebum plugs the canal and accumulates there. Soon, the bacteria present on the skin surface, namely Propionibacterium acnes, invade these clogged ducts and attract white blood cells of the immune system. The infected area becomes inflamed due to the reaction between white blood cells and the bacteria.

The development of acne takes place over 2-3 weeks before it appears on the surface of the skin. It starts as a blemish in the sebaceous hair follicle. Deep within the hair follicle, two processes continually take place. The produced sebum mixes with old, dying cells and gets excreted through the hair follicle pores. Old cells die so that new cells can be generated and skin can rejuvenate itself.

In normal circumstances, the dead cells that are shed gradually keep pace with the formation of new cells. This shedding of skin cells is different in different people. In some people, the skin sheds dead cells evenly. In other cases the shedding of the skin becomes uneven and the dead cells accumulate in the follicles, thus effectively plugging the pore with sebum and bacteria.

Acne can be non-inflammatory or inflammatory. Non-inflammatory acne is the common form of acne called comedo. When a comedo’s pore is closed and the plug remains inside the skin, it is called a whitehead. These appear on the skin as small, whitish bumps.

When the pore is open and the plug pushes through the skin on the outer surface, it is called a blackhead. The opening of this blackhead appears dark in color not because of the accumulation of dirt, but due to the build up of pigment melanin.