Causes
The most common cause is hormonal changes that stimulate oil production in the sebaceous (oil-producing) glands of the skin. Together with dead skin cells and bacteria, this oil (sebum) blocks the pores causing acne to develop. Acne is often worst during puberty as testosterone levels increase, which can cause an over-production of sebum.

Premenstrual hormonal changes can also trigger acne. Poor diet, nutritional deficiencies, stress and anxiety may play a part too.

Orthodox treatments
Skin creams and gels containing benzoyl peroxide are used to unblock the pores, while antibiotics may be prescribed if the pores have become infected. Other creams based on vitamin A may be used to reduce sebum production, but these can cause side effects.

Oral contraceptives are sometimes prescribed to young women with hormone-related skin problems. Cosmetic surgery may be recommended for severe facial scarring.

Complementary treatments
Herbal medicine - Chinese, Ayurvedic, Tibetan and Japanese herbal formulas are all used to treat acne.

Nutritional and dietary therapy - acne sufferers are often deficient in zinc. Supplementation with zinc, vitamin A, vitamin E and selenium has been found to reduce acne. Decreased intake of fried, sugary and fatty foods and dairy produce combined with increased intake of fresh produce, vegetables, wholegrains and fibre often helps. Food intolerance testing is sometimes useful.

Acupuncture - can be effective, particularly if there are associated digestive problems.

Homeopathy - kali bichromicum is sometimes used for itchy spots, sulphur for painful, infected pores and hepar sulphuris for very sensitive and irritated skin.

Psychological therapies - autogenic training, relaxation therapy, biofeedback and cognitive imagery have all been used with some success.

Light therapy - exposure to light (phototherapy) may help.

Self-help tips
Cleanse the affected skin twice a day with an antibacterial face wash. Tea tree or neem products are ideal. Witch hazel is another potent skin cleanser.
Keep your hands and nails clean. Avoid touching your face and never squeeze spots as this can spread infection and lead to scarring.
Treat spots by applying a small amount of tea tree oil on a cotton bud. Use sparingly, though, and do a skin test first on an area away from the face. Don't use near the eyes.
Eat a healthy diet with plenty of fresh vegetables, fruits and wholegrains. Keep saturated fats, sugar, junk food to a minumum and avoid excess animal or dairy products.
Have a daily intake of zinc-rich foods (found in wholegrains, pulses, nuts and seeds, fish and poultry) or supplement with zinc citrate or zinc picolinate (30mg to 50mg a day) every evening taken on its own with water.
Reduce tea and coffee intake and increase your water intake to at least six glasses a day.
Take regular exercise and practise deep breathing; both help to release impurities from the skin.