In our blog, Toronto dermatologist Dr. Michelle Levy writes about common skin problems, controversies and developments, and provides science-based answers to common questions.
In my practice as a dermatologist, I frequently have patients tell me that they are concerned about using cortisone creams because they have heard that they thin the skin. While it is true that strong topical cortisones can thin the skin, in practice, this is very uncommon with milder creams, especially when they are used properly.
Steroids are hormones that decrease inflammation in many ways, including by acting on the body's immune cells. Steroids in ointments or creams have been safely used in the treatment of skin diseases since the 1950s. There are dozens of topical steroids (cortisones) on the market today in Canada and the US. These medications are divided into seven classes, mainly based on their chemical structure. Class 1 steroids are the strongest and are up to 600 times more potent than class 7 steroids such as hydrocortisone. Cortisones from other classes fall somewhere in-between.
Apart from its chemical structure, factors that influence the potency of a topical steroid include the type of vehicle the medication is in (greasy ointments are more potent than creams), the concentration of the active ingredient, and the type of skin to which it is being applied. Thin-skinned areas such as the face or eyelids will absorb a medication much more readily than thick-skinned sites such as the back or palms. For this reason, dermatologists will typically choose a mild cortisone for the face and a stronger product for the body.
Skin thinning is rarely seen with the proper use of mild or even mid-strength topical steroids. A study of 70 children with eczema that was published in 2011 found no evidence of skin thinning in children who were using moderate and strong topical cortisones intermittently (not on a continuous basis) for at least 3 months.
An important exception occurs when a mid or high-potency cortisone is applied to the “folds” of skin; the underarms, groin or underneath the breasts. Cortisones used in these areas undergo "occlusion" and become much more potent. Permanent stretch marks can develop with the use of a mid or high potency steroid in these areas after relatively brief periods of time.
The side effects of cortisone creams can best be avoided by using these creams intermittently, and by using the right product on the right part of the body. Medicated creams are usually used 1-2 times per day when a rash (such as eczema or psoriasis) is active, and stopped once the skin is healed. There are various measures that can then be used to maintain the improvement achieved by the cream; speak with your dermatologist about how to use your prescription medicine properly.
What is the Bottom Line?
When used properly, most topical cortisones have an excellent safety profile. Skin thinning is uncommon with short-term or intermittent use, and is often reversible when it occurs. Hydrocortisone is the weakest of the topical steroids and it would be very unlikely to cause skin thinning when used properly.
Mid and high potency topical steroids should only be used under a doctor's supervision, and instructions for use should be followed carefully. Applying a strong topical steroid too liberally or too frequently, or using it in areas for which it was not intended can indeed result in unwanted side effects.