What are topical retinoids?
Topical retinoids are creams, lotions and gels containing one or other of group of medicines derived from Vitamin A. These compounds result in proliferation and reduced keratinisation of skin cells independent of their functions as a vitamin.
Many brand-name creams containing the retinoids retinol and retinaldehyde can be obtained over the counter at pharmacies and supermarkets.
The more potent topical retinoids available on prescription in New Zealand are:
- ReTrieve™ cream (tretinoin) – fully funded in New Zealand since 1 July 2010
- Retin-A™ Cream (tretinoin or retinoic acid)
- Retinova™ Cream (tretinoin emollient)
- Isotrex™ Gel (isotretinoin)
- Differin™ Gel, Cream (adapalene) – fully funded in New Zealand since 1 October 2010
Adapalene is also available to treat acne in combination with benzoyl peroxide, as Epiduo® gel.
What are they used for?
Topical retinoids are effective treatments for mild to moderately severe acne. The effect is often noticeable within a few weeks, but it may take 6 weeks or longer before improvement occurs.
Tretinoin has also been shown to reverse some of the changes due to photo-aging, i.e. sun damage. If used long term, it may reduce some fine wrinkles, freckles, solar comedones (whiteheads and blackheads), and actinic keratoses (tender, dry sun-spots).
Topical retinoids can be applied to any area but are most often used on the face, the neck and the back of hands.
Do they have any side effects?
Retinoids can irritate the skin, especially when they are first used. This is more likely in those with sensitive skin, resulting in stinging. Excessive use results in redness, swelling, peeling and blistering in treated areas. It may cause or aggravate eczema, particularly atopic dermatitis.
By peeling off the top layer of skin, they may increase the chance of sunburn. Irritation may also be aggravated by exposure to wind or cold, use of soaps and cleansers, astringents, peeling agents and certain cosmetics.
Some people have reported a flare of acne in the first few weeks of treatment. This usually settles with continued use.
Retinoids taken by mouth may cause birth deformities. Manufacturers recommend that topical retinoids are not used in pregnancy or breastfeeding as negative animal studies are not always predictive of human response.
How to use topical retinoids
Follow these instructions carefully:
- Be cautious if you are using other topical acne treatments – ask your doctor if you should stop these.
- In general, a cream is less iritating than a gel. If there is a choice, start with a lower concentration product.
- Use your topical retinoid on alternate nights at first. If you have sensitive skin, wash it off after an hour or so. If it irritates, apply it less often. If it doesn't, try every night, and if possible twice daily. In most people, the skin gradually gets used to it.
- To reduce stinging, apply it to dry skin, that is, 30 minutes or longer after washing.
- Apply a tiny amount to all the areas affected, and spread it as far as it will go.
- Don't get it in your eyes or mouth.
- Apply a sunscreen to exposed skin in the morning.
- Wear your usual make-up if you wish, and use gentle cleansers (avoid soap) and apply non-greasy moisturisers as often as required.
- If you have acne, choose oil-free cosmetics.
- If your skin goes scarlet and peels dramatically even with cautious use, the retinoid may be unsuitable for your sensitive skin.
- Tolerance to topical retinoids often develops over time.