Acne is the inflammation of the oil glands of the skin. The oil glands of the skin are known as sebaceous glands and produce sebum. The glands vary in size during life and become enlarged during teenage years with the onset of puberty.


The production of sebum is under the control of the male sex hormones particularly testosterone in males. The exact link with hormones in females is not as clear, though females have some of these androgens (male hormones) naturally, though at low levels.


The sebaceous gland secretes sebum into the hair follicle and the sebum then passes out through the duct to the surface of the skin, keeping the skin supple. The sebum also has antibacterial properties keeping the numbers of harmful bacteria low.

The sebaceous glands are found on the face, back and chest which are the areas that acne is found. So what happens to cause acne?


There are four components....


1) Increased sebum production

Those who suffer with acne on average secrete more sebum than those who do not have acne and the more sebum that is excreted the more severe the acne can be. This is controlled by the androgenetic hormones, which includes testosterone. So, if there are increased levels of testosterone then more sebum is excreted possibly leading to acne. This is the case in certain diseases where testosterone is produced, however this is not the case in normal teenage acne.

The theory is that the sebum glands of those who suffer with acne are more sensitive to the hormones and secrete more sebum than they should. Producing more sebum is NOT due to eating fatty foods. This excess production of sebum is caused by the genes of the person, in other words, the way someone is made.


2) Blockage of the duct

The duct of the oil gland becomes blocked in those who suffer with acne. This is called ductal hypercornification. This leads to the production of comedones which are otherwise known as blackheads and whiteheads. The more comedones a person has the more severe the acne can be. This can be regarded as causing “blockage” of the duct so the sebum does not flow freely out of the duct.

Blackheads are NOT caused by not cleaning or washing enough or being dirty and the black discolouration is caused by the sebum being oxidised. Scrubbing and scouring the skin will not stop or clear blackheads and can cause problems in itself.


3) Bacteria

Acne is NOT infectious and cannot be passed on from one person to another. However, it is noted that bacteria are involved with the cause of acne, but not the types of bacteria that cause boils, impetigo or wound infections. The bacteria linked with causing acne is called Propionibacterium acnes (P.Acnes) and colonises the sebum in the sebaceous glands and ducts.


4) Excess inflammation

The exact cause of the inflammation in acne is not known but it is possible that it is the chemicals that are made by the p.acnes that cause the immune system to cause excessive inflammation.







Why do certain people get acne?

It is all about how you are made. In those people who have acne, one or more of their parents is most likely to have had acne. This indicates the genetic cause of the condition. The exact genes that are linked with acne are not known and it is likely to be a combination of a few different types of genes that are inherited from an individual’s parents.


Acne, known as acne vulgaris is a common problem faced by adolescents. Up to 95% of boys and 85% of teenage girls experience a degree of acne with milder spots. Approximately 15% of teenagers suffer from more significant acne that may cause scarring. This may leave marks on the skin and also affecting sufferers emotionally, requiring the help of a doctor.


Acne in teenage girls versus boys

Acne starts earlier in girls than in boys.


In females acne usually starts between 14 and 17 years with the worst acne during this time and after 17 years it will be improving by itself.In males the acne usually starts between 16 and 19 years old with the worst acne occurring during this time. It also improves after this time naturally.


Acne persisting after teenage years

Acne improves and clears towards the end of teenage years, but in some it may go on to the mid twenties. Acne can persist for several years and approximately 7% of people aged 28 – 40 years are affected, particularly women. In some people for reasons that are not fully understood the acne can develop for the first time after the age of 25.


Younger onset acne

In some children as young as 8 years old the first signs of acne may appear, such as the red papules, comedones (blackheads and whiteheads). Treatment may be required at this stage depending on the degree of scarring and how the person is affected emotionally by the acne.