Toronto dermatologist Dr. Michelle Levy writes about common skin problems, controversies and developments, in our dermatology blog, and provides science-based answers to common questions.
Hyperpigmentation, in which patches of skin become darker than the rest of the skin, is a common concern among my patients, and lightening creams are an important part of the way in which I treat this problem. Most of the time, when dermatologists speak of "bleaching creams" they are referring to those products that contain hydroquinone, a naturally-occurring chemical that decreases the skin's production of pigment (melanin), and has long-been considered the "gold standard" in skin lightening. Recently, questions have been raised over whether or not hydroquinone is safe, and I think a discussion of the risks and benefits of creams that contain this ingredient is important.
In Canada, hydroquinone is found in over-the-counter lightening creams in concentrations of up to 4% (in the US concentrations above 2% are by prescription), and stronger preparations can be prepared by pharmacists. In the US and Europe, hydroquinone can be found as part of "triple combination creams", that also contain tretinoin (a cousin of vitamin A) and a mild cortisone. In Canada, dermatologists will frequently have a similar product prepared for use by pharmacists who will compound (mix) these ingredients together.
What are bleaching creams used for?
Some of the common causes of uneven pigmentation that may be treated with lightening creams include:
Melasma: hormone-induced pigmentation that results in brown patches, most commonly seen on the face in women
Solar lentigines ("sun spots"): sharply-defined small brown spots seen on sun-exposed skin
Post-inflammatory hyperpigmentation: discolouration that sometimes results after the skin has been inflamed, most commonly in individuals with darker skin tones
What are the side effects of hydroquinone?
Skin Irritation is common with the use of hydroquinone, and is the reason it is frequently combined with mild cortisones, as cortisones decrease inflammation. Irritation is common when someone first starts using a hydroquinone-containing cream and tends to improve over the first 2-3 weeks of use.
Allergy is an uncommon side effect but allergic eczema can rarely result from hydroquinone use
Exogenous Ochronosis is a rare condition in which the use of hydroquinone can lead to bluish dark patches on the skin which are difficult to treat. Thankfully this side effect is quite rare, and is usually seen with long-term use (years) of creams that contain this ingredient. The vast majority (>95%) of reported cases of exogenous ochronosis come from Africa, and it is thought that perhaps other ingredients (such as resorcinol) that have been combined with hydroquinone in lightening creams that have been used in Africa increase the risk of this problem.
Permanent skin lightening is extremely rare but has been reported in a small number of people who have been exposed to hydroquinone.
Never purchase lightening creams that have been imported into the country and are not sold at a reputable pharmacy with the ingredients clearly marked on the labels. Illegally-imported lightening creams have been found to contain high levels of hydroquinone, strong topical cortisones, or in some cases even mercury. These creams can result in side effects that are not only unwanted, but in the case of mercury are downright dangerous.
Do creams that contain hydroquinone cause cancer?
Concern has been raised about the use of hydroquinone because of a few studies that have found increased rates of certain cancers when rats were fed or injected with large quantities of this chemical. Many dermatologists think that these risks are specific to rats ingesting hydroquinone, and do not apply to people using these creams on their skin. Indeed, several animal studies in which hydroquinone was applied to the skin of rats and mice showed no evidence of toxicity as a result of this exposure. It should also be noted that hydroquinone is found naturally in many foods such as berries, tea, coffee, red wine and pears.
Hydroquinone has been widely used all over the world for over 50 years. It is estimated that 10-15 million tubes of creams containing this ingredient are sold in the United States alone each year, and there are over 100 medical studies describing the use of this chemical in the treatment of skin conditions. Despite this, there is not a single report in the scientific literature of cancer resulting from the use of hydroquinone-containing creams. While there have been a few cases of cancer reported in individuals exposed to very high levels of hydroquinone over many years through their occupations, larger studies (which are usually considered to be more reliable than individual reports) have shown no increased risk, and in some cases even a decreased risk of cancer among workers exposed to high doses of this chemical. Based on the current scientific evidence, most dermatologists believe that short-term and intermittent (non-continuous) use of topical hydroquinone creams carries a low risk of side effects, with no evidence that this treatment causes cancer in human beings.
I've read that hydroquinone has been "banned" in Europe. Is that true?
Despite reports to the contrary on the internet, hydroquinone is not banned from use in the European Union. It is not available over-the-counter, but can be obtained by prescription.
Are there alternatives to using creams containing hydroquinone?
There are a number of non-hydroquinone skin lightening products on the market. It is generally believed that these are not quite as effective as those that contain hydroquinone, but for mild hyperpigmentation, or for those concerned about the side effects of hydroquinone, they may be a good option.
Ingredients that have been shown to have skin lightening properties include azaleic acid, arbutin, licorice extract, soy, kojic acid, niacinamide, vitamin C, and retinol, among others. A number of commercial products on the market contain a mixture of several active ingredients in an attempt to provide more meaningful results. Examples include Skin Medica's Lytera, Derma E Skin Lighten Natural Fade & Age Spot Cream, and Obagi's Skin Brightening Complex.
What's the bottom line?
Hydroquinone has been widely used to treat hyperpigmentation for over 50 years with very few reports of problems developing in people who have used creams that contain this ingredient. Side effects can occur with the use of hydroquinone, the most notable of which is the rare development of a skin condition known as exogenous ochronosis. In order to minimize the risk of side effects, creams that contain this ingredient are ideally used in brief cycles of 3-6 months, and longer-term use should be supervised by a physician. In all cases of hyperpigmentation, strict sun-protection is a must...otherwise these problems worsen and frequently recur.
Pigmentary problems are often highly distressing to those who experience them, and my patients frequently want the best treatment available for this issue. At the moment, hydroquinone-containing creams appear to be the most effective topical treatment available for many types of hyperpigmentation. While a great deal of research and clinical experience support the safety of this compound, side effects can rarely occur, and those choosing to use these creams should be aware of their risks and benefits. Alternatives to hydroquinone do exist and their effectiveness continues to improve. See a board-certified dermatologist for medical advice and to learn more about the treatment of pigmentary problems.
How should I use lightening creams that contain hydroquinone?
While over-the-counter preparations that contain hydroquinone can be used for short periods of time, use of higher concentrations of hydroquinone, or prolonged use of this chemical should be supervised by a physician. The following are guidelines for the use of hydroquinone-containing products:
1. Apply a thin layer of the cream to clean, dry skin. Some hydroquinone-containing products are to be used only at night, while others are used twice daily. Follow your doctor's instructions.
2. Apply only to dark patches. Do not use hydroquinone on your whole face. Avoid the mouth and eyes.
3. Start slowly. Use the cream three times per week to start and slowly increase as tolerated. If your skin becomes irritated and red, stop using the product and use only a moisturizer for a few days. Re-start the product more slowly and use it less frequently. In many cases, minor irritation subsides after the first 2-3 weeks of using hydroquinone-containing products. If irritation persists, stop using the product and contact your doctor.
4. Treat the underlying cause of hyperpigmentation. For example, if you have acne that is causing dark sports, treat the acne to prevent further discolouration.
5. Use a "broad spectrum" sunscreen with an SPF of 30 or higher every single day (yes, even in the winter). Those with melasma may do best with a mineral sunscreen that contains zinc oxide. Wear a hat and avoid direct sunlight as best you can.
6. Limit use to 3-6 months at a time. Consider alternating with a non-hydroquinone skin lightener in 4 month cycles.
7. If your medication turns brown it is less effective and you'll need to refill it.
8. Do not use products that contain benzoyl peroxide at the same time as those containing hydroquinone as this can result in a temporary staining of the skin.
Because some hydroquinone is absorbed through the skin, it should not be used by pregnant women or by nursing mothers.
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