Health encyclopaedia - Alphabetical Topic List
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Causes of Acne
Acne that begins at puberty is the result of increased sensitivity to the hormone testosterone, which is present in both boys and girls. Testosterone causes excessive sebum to be secreted from the skin’s sebaceous glands. Skin cells rapidly divide and sometimes block the opening of hair follicles. The resulting build up of sebum behind the blockage helps produce blackheads and whiteheads.
At puberty changes in skin acid levels also encourage the growth of bacterium, which can become trapped in the hair follicles. This produces a deeper infection, in the form of pustules and nodules.
Other causes:
- Acne sometimes seems to run in families, so there may be a genetic factor that makes certain people more likely to have it.
- Acne may become worse in times of stress, although it is not clear why. It may be because stressed people touch their faces more, spreading the bacteria, or because they are sweating more.
- In girls, outbreaks may be affected by the hormonal changes that occur during the menstrual cycle.
- Another cause may be excessive production of androgens (hormones like testosterone), resulting not from puberty but from conditions such as polycystic ovary syndrome (PCOS).
- Certain drugs such as corticosteroids, anti-epileptic medicines like phenytoin, and oral contraceptives containing levonorgestrel or norethisterone, may aggravate acne.
- Anabolic steroids, sometimes used by body-builders, can cause acne as a side-effect.
- Exposure to dangerous chemicals called dioxins can cause a rare form of acne called chloracne.
Eating greasy foods or chocolate does not cause acne. Having poor hygiene is also not a direct cause, although if you do not wash your face or remove make-up, bacteria will be able to multiply on your skin.
