'I had a facial and they left a glycolic peel on for too long,' Wong says. 'So I thought that might have caused it.'

But the rash persisted. 'Then I kept thinking it was something I'd eaten. I thought my skin was dry so I added more and more cream.'

Eventually she decided to use the cream intermittently and the rash subsided. Then one night she rubbed it in before she went to bed and the next morning found that her rash had reappeared.

'I'm pretty sure this was the source of my rash as I haven't had any problems since I stopped using the products.'

In America, a survey by the US Food and Drug Administration found almost a quarter of people reported an allergic reaction to personal care products, including moisturisers, foundations and eye shadows. Symptoms can appear after just one or two uses or sometimes they develop after years of use without prior problems.

Dermatologist Louis Shih Tai-cho says skin reactions are on the rise in Hong Kong because people are increasing their use of such products.

'People are more aware of their skin's appearance and there are more products on the market to target a variety of problems from dark spots to wrinkles,' Shih says. 'A lot of times these advertisements are lies and people are lured into using cosmetics they don't need. For instance, claims of vitamins in products to reduce wrinkles cannot replace vitamins from a healthy diet.'

Shih says there are two types of skin reactions to beauty products that can develop. The first is irritant contact dermatitis - the most common reaction, identified by itchy, dry, red or blistered skin in the area where the product is applied.

Shih says some people can even develop secondary infections from this because the skin becomes broken from the dryness. Irritation is linked to the concentration of a certain ingredient.

The second type of reaction is allergic contact dermatitis, which is known as a sensitivity or a true allergy that's linked directly to an ingredient. It can also cause redness, swelling, itchy or blistered skin.

Fragrances and preservatives often cause allergic reactions, says Shih. But they are difficult to identify because not all brands list every ingredient and sometimes ingredients are given different names.

If it's perfume that you're allergic to, look for products marked fragrance-free or without perfume but be aware that some of these products may still contain a masking agent or a fragrance used to cover up chemical scents.

The most common preservatives used to inhibit the growth of bacteria in beauty products sound like a nasty chemistry experiment. They include parabens, imidazolidinyl urea, quanternium-15, dimethyl-dimethyl (DMDM) hydantoin and phenoxyethanol. Shih says it's important to be cautious with products that contain higher concentrations of water, such as mascara, liquid eyeliners and foundations as these oxidise as soon as they are exposed to air, producing bacteria.

Permanent hair dyes, especially those containing phenylenediamine or ammonium persulfate can be particularly problematic, with up to 10 per cent of users suffering allergies, Shih says.

According to Hong Kong family doctor Lauren Bramley, these skin conditions stem from inflammation, which research shows is the main contributor to all sorts of ailments from cardiovascular problems to respiratory illnesses, arthritis and gastrointestinal disorders.

'If you are experiencing an increase in these skin reactions there is a good chance it could be related to other systemic problems or symptoms,' says Bramley.

So what should you do if the products you're using are doing more harm than good?

Shih says it's important to do a test patch on your neck or inner arm before using a new product to prevent a reaction. 'If you develop a reaction, stop using your products,' he says. 'Then use [them] one at a time and this way you can find the culprit by elimination and isolate the problem.'

Bramley says it's difficult to identify which ingredients are the worst culprits as it usually varies between individuals. 'Some people will react to products that others may tolerate but as a rule of thumb we see more problems with products with harsher chemicals such as acid peels, retin-A, and bleaches,' she says.

She adds that if you react to a new product, common sense tells you to discontinue using it.

'But what to do when you start having problems with a trusted product or find your skin is reacting to everything?' she says. 'Don't toss those expensive products in the bin. I recommend you put them on the shelf for a moment while we get the skin condition under control and hopefully improve your body's ability to detoxify and decrease inflammation at the same time.'

Bramley says the good news is some basic intervention may not only clear up your skin, but also help with your overall health.

'Two simple, safe, and inexpensive tools that I have found improve all of these sorts of skin problems are omega 3 and vitamin D supplements. Many of us are shockingly low in these two vital substances which are major players in cancer prevention, cardiovascular health, bone and joint function, immune and allergic responses, behaviour and mental health, digestion, as well as healthy skin.'

In nature, we get our essential omega 3 fatty acids primarily from deep water fish and vitamin D (actually a potent steroid hormone) from skin exposure to sunlight. But in reality, precious few of us get an adequate amount of either, she states.

'When a patient presents with a skin reaction, we will initially treat it symptomatically while initiating some of the more general measures described above. To speed recovery and minimise future reactions, use very mild, natural topical products such as a low-dose vitamin C serum, vitamin B5 gel and topical omega 3 cream.'

Shih recommends buying products from the big brand names. 'These are not necessarily the expensive ones but big brands have good research and backing - they can't afford to have an accident because it would damage their reputation.'

He also cautions to be wary of companies making claims of hypoallergenic, organic or natural as there's nothing requiring companies to produce proof of their claims.

'You can still be allergic to these products as some companies will put these claims on their products without any investigation. I would advise consumers to get advice from their GP or pharmacist on what they should use.

'Look for products that are simple - without too many ingredients as this lessens your exposure and chance of reaction.'