Acne blights many teenage lives, and can persist into adulthood too. But there are ways to keep the bumps away

ACNE Vulgaris. It says it all, doesn't it? Painful red plooks that are unpleasant to look at but even worse for the person unfortunate enough to be suffering from them.

It's a common enough complaint. Around 80 per cent of teenagers have spots at some point, which makes the recent recruitment of teen heart throb Justin Bieber as the face of an acne treatment pure genius.

"I know that for a teenager, it doesn't matter how many people are looking at you, you don't want acne on your face," says the 16-year-old popster. "I'm in the limelight all the time. I'm constantly doing interviews, constantly doing photo shoots and, you know, I'm determined to keep myself clear."

But however unglamorous his new role might seem, it's unlikely to affect his career adversely; Jessica Simpson, Katy Perry and Avril Lavigne have all represented the same brand, Proactiv, in the past.

"I got acne at the start of my career," Perry has said. "It was a stressful time. I have acne scars. I'm self-conscious about that, so sometimes I wear too much make-up to cover them up." Her contract with Proactiv was reportedly worth millions of dollars. Zits, it seems, are big business.

Caused by the creation of excess oil in the sebaceous glands, which blends with dead skin cells to form a plug in the hair follicle, this can then be contaminated by bacteria living on the skin, causing spots to form, most commonly on the face, back and chest.

The usual reason for all this sebaceous activity is an increase in the amount of testosterone being produced in the body during puberty. For most of us, the skin clears up by the time we reach our twenties, but around five per cent of women and one per cent of men continue to experience symptoms beyond the age of 25.

"Acne can develop for first time after the age of 25," says Dr Bav Shergill, consultant dermatologist and spokesperson for the British Association of Dermatologists. "And although not as common as teenage acne, the number of cases of late-onset acne has increased in recent years. One recent study estimated that 14 per cent of women in the UK aged between 26 and 44 suffer from it."

Cameron Diaz, Britney Spears, Tom Cruise and Brad Pitt are among the most famous. Victoria Beckham, too, has been known to have the occasional spot. Her adult acne is caused by polycystic ovary syndrome, and she was at one stage said to be importing a special food, called Natto, from Japan, in a bid to beat the break-outs.

So, first, the bad news. There is no known cure. And at its most severe, it can result in anxiety, stress and even depression. But, on the plus side, most people can be treated effectively. So if you're having no joy with over-the-counter remedies, fear not. A GP can prescribe a range of different treatments, from creams and antibiotics to oral contraceptive and a drug called Isotretinoin, which can only be prescribed by a dermatologist.

"Isotretinoin is still the most effective anti-acne drug that I use for severe acne cases," says Dr Shergill. "However, this is a powerful treatment which has the potential to cause a number of serious side-effects. I am also currently using fractional carbon dioxide laser technology to treat certain types of acne and acne scarring, with some success.

"The important thing to remember is that everyone's acne must be treated individually, and the key advice with any treatment is to make sure you stick with treatment as it can take several months to work."

Contrary to popular opinion, spots are not infectious, nor are they caused by poor hygiene. Interestingly, a fatty or unhealthy diet may also be off the list of usual suspects.

"The jury's still out on the impact of food on acne," says Dr Shergill. "But it may be sensible for you to avoid foods that you think make your acne worse.."

However, one lifestyle factor that has been proven to trigger problem skin is smoking. "Scientists have recently identified a new skin disorder called 'smoker's acne'," explains Dr Shergill. "Characterised by blocked pores and large blackheads, it seems to particularly affect adult female smokers.

"The study found that 42 per cent of smokers had acne compared to only one in ten non-smokers. And smokers who had acne in their teens were found to be four times more likely to suffer acne as an adult than non-smokers who also had experienced teenage acne."

The temptation to pick should be avoided at all costs. "But whether or not to squeeze depends on the spot. If it has a white head it may be fine, but if it is red and inflamed, it is definitely best to leave it as you will only damage the skin."

And if all else fails, consider Cameron and Cruise, who have proved that, even if you suffer from problematic pimples, a dazzling smile is best concealer you can find.

• This article was first published in the Scotland on Sunday on August 29, 2010