• While a great deal is known about Acne, the primary cause still is not known and thus there is no cure for acne.

Overactive sebaceous glands

• There can be no acne without sebum and this requires an active sebaceous gland. Sebum forms a protective coating over the skin surface and preserves the skin barrier by preventing water evaporation from the skin surface to the environment. However, sebum is necessary for acne and the amount of sebum produced correlates with the severity of the acne.
• There are several factors that drive sebum production. One of the major driving factors is male hormones, known as androgens, which explains the increased severity of acne found in males rather than females. However, the androgenic balance is abnormal in 50-75% of females with acne. Some women have a hormone imbalance due to polycystic ovary disease, where the ovarian hormone production is abnormal.

Bacteria

• The excess sebum production clogs the openings of the hair follicles. Bacteria then grow in these follicles.
  
• The outer horny layer of the epidermis is usually dead. It is constantly shedding thousands of keratinised cells.
• We are unaware of it because the cells are microscopic in size.
• The surface of the face is covered with sebaceous follicles that are long hollow tubes not much bigger in diameter than a hair. The walls of the follicle are lined with the same dead cells that are on the outside of the face. Hence the same constant shedding takes place in the sebaceous follicle.
• Normally glue like substance, called intercellular glue, carries these dead cells to the surface where they are eventually shed. However, in people who are genetically prone to acne, these cells stick together in the follicle and cannot reach the surface and cause a blockage called micro comedones.
• At this stage the process is developing in the follicle only and the surface of the skin may appear entirely clear and unaffected. As the process continues, the blockage worsens and oils and bacteria build up. The bacterium subsequently excretes a nasty inflammatory acid by-product that leads to various acne lesions.

• Open Comedones (Blackheads)

  In order to accommodate the accumulation of dead cells and oils the follicle forces the opening wider and appears as enlarged pores or blackheads.

• Papules/Pustules/Nodules/Cysts

  Should the opening of the follicle be closed, the blocked follicle will expand to accommodate the increasing accumulation of dead cells/oil/fatty acids/bacteria may progress into a papule/pustule/nodule/cyst.

• The follicle will continue to expand until it looks like a little bulging round ball. Follicles at this stage can only stretch so far and can be categorised as time bombs ready to explode. Stress, menstrual cycle, lack of sleep and other factors provide the trigger for the bomb to explode. This explains one of the reasons why the acne is frustratingly inconsistent.
• As the time bomb explodes, the contents of the follicle leak out into the surrounding tissue causing severe inflammation. After the infection has subsided, the severity of the lesion and the scarring of the skin depend on the size and contents of the ruptured follicle.
• The most severe eruption is the cyst that occurs when a follicle ruptures in the dermis to cause destruction of collagen and elastine leading to superficial scarring or deep pitting on the skin.