What are topical steroids and how do they work?
Topical steroids are creams, ointments and lotions which contain steroid medicines. Topical steroids work by reducing inflammation in the skin. They are used for various skin conditions including eczema. (Steroid medicines that reduce inflammation are sometimes called corticosteroids. They are very different to the anabolic steroids which are used by some bodybuilders and athletes.)
What types of topical steroids are there?
There are many types and brands of topical steroid. However, they are generally grouped into four categories depending on their strength – mild, moderately potent, potent and very potent. There are various brands and types in each category. For example, hydrocortisone cream 1% is a commonly used steroid cream and is classed as a mild topical steroid. The greater the strength (potency), the more effect it has on reducing inflammation but the greater the risk of side-effects with continued use.
Creams are usually best to treat moist or weeping areas of skin. Ointments are usually best to treat areas of skin which are dry or thickened. Lotions may be useful to treat hairy areas such as the scalp.
When and how are topical steroids used?
As a rule, a course of topical steroid is used when one or more patches of eczema flare up. The aim of treatment is to clear the flare-up and then to stop the steroid treatment.
It is common practice to use the lowest strength topical steroid which clears the flare-up. So, for example, hydrocortisone 1% is often used, especially when treating children. This often works well. If there is no improvement after 3-7 days, a stronger topical steroid is usually then prescribed. For severe flare-ups a stronger topical steroid may be prescribed from the outset.
Sometimes two or more preparations of different strengths are used at the same time. For example, a mild steroid for the face and a moderately strong steroid for patches of eczema on the thicker skin of the arms or legs. A very strong topical steroid is often needed for eczema on the palms and soles of the feet of adults because these areas have thick skin.
You should use topical steroids until the flare-up has completely gone and then stop it. In many cases, a course of treatment for 7-14 days is enough to clear a flare-up of eczema. In some cases, a longer course is needed.
Many people with eczema require a course of topical steroids every now and then to clear a flare-up. The frequency of flare-ups and the number of times a course of topical steroids is needed varies greatly from person to person.
After you finish a course of topical steroid, continue to use emollients every day to help prevent a further flare-up. See separate leaflet called ‘Emollients (Moisturisers) for Eczema’ for more details.
Short bursts of high-strength steroid as an alternative
For adults, a short course (usually three days) of a strong topical steroid may be an option to treat a mild-to-moderate flare-up of eczema. A strong topical steroid often works quicker than a mild one. (This is in contrast to the traditional method of using the lowest strength wherever possible. However, studies have shown that using a high strength for a short period can be more convenient and is thought to be safe.)
Short-duration treatment to prevent flare-ups (weekend therapy)
Some people have frequent flare-ups of eczema. For example, a flare-up may subside well with topical steroid therapy. But then, within a few weeks, a flare-up returns. In this situation, one option that might help is to apply steroid cream on the usual sites of flare-ups for two days every week. This is often called weekend therapy. This aims to prevent a flare-up from occurring. In the long run, it can mean that the total amount of topical steroid used is less than if each flare-up were treated as and when it occurred. You may wish to discuss this option with your doctor.
How do I apply topical steroids?
Topical steroids are usually applied once a day (sometimes twice a day – your doctor will advise). Rub a small amount (see ‘Getting the dose right – the fingertip unit’, below) on to areas of skin which are inflamed. (This is different to emollients which should be applied liberally all over.) Gently rub the cream or ointment into the skin until it has disappeared. Then wash your hands (unless your hands are the treated area).
Getting the dose right – the fingertip unit
The amount of topical steroid that you should apply is commonly measured by fingertip units (FTUs). One FTU is the amount of topical steroid that is squeezed out from a standard tube along an adult’s fingertip. (This assumes the tube has a standard 5 mm nozzle.) A finger tip is from the very end of the finger to the first crease in the finger.
One FTU is enough to treat an area of skin twice the size of the flat of an adult’s hand with the fingers together.
Two FTUs are about the same as 1 g of topical steroid. For example, say you treat an area of skin the size of eight adult hands. You will need four FTUs for each dose. (This is 2 g per dose. If the dose is once a day, then a 30 g tube should last for about 15 days of treatment.)
The following are further examples:
|Area of skin to be treated (adults)||Size is roughly||FTUs each
|A hand and fingers (front and back)||About 2 adult hands||1 FTU|
|Front of chest and abdomen||About 14 adult hands||7 FTUs|
|Back and buttocks||About 14 adult hands||7 FTUs|
|Face and neck||About 5 adult hands||2.5 FTUs|
|An entire arm and hand||About 8 adult hands||4 FTUs|
|An entire leg and foot||About 16 adult hands||8 FTUs|
Fingertip units and children
An FTU of cream or ointment is measured on an adult index finger before being rubbed on to a child. Again, one FTU is used to treat an area of skin on a child, equivalent to twice the size of the flat of an adult’s hand with the fingers together. You can gauge the amount of topical steroid to use by using your (adult) hand to measure the amount of skin affected on the child. From this you can work out the amount of topical steroid to use.
The following gives a rough guide:
For a 3-6 month-old child:
- Entire face and neck – 1 FTU.
- An entire arm and hand – 1 FTU.
- An entire leg and foot – 1.5 FTUs.
- The entire front of chest and abdomen – 1 FTU.
- The entire back including buttocks – 1.5 FTUs.
For a 1-2 year-old child:
- Entire face and neck – 1.5 FTUs.
- An entire arm and hand – 1.5 FTUs.
- An entire leg and foot – 2 FTUs.
- The entire front of chest and abdomen – 2 FTUs.
- The entire back including buttocks – 3 FTUs.
For a 3-5 year-old child:
- Entire face and neck – 1.5 FTUs.
- An entire arm and hand – 2 FTUs.
- An entire leg and foot – 3 FTUs.
- The entire front of chest and abdomen – 3 FTUs.
- The entire back including buttocks – 3.5 FTUs.
For a 6-10 year-old child:
- Entire face and neck – 2 FTUs.
- An entire arm and hand – 2.5 FTUs.
- An entire leg and foot – 4.5 FTUs.
- The entire front of chest and abdomen – 3.5 FTUs.
- The entire back including buttocks – 5 FTUs.
Using topical steroids and emollients together
Most people with eczema will also use emollients (moisturisers). Emollients are different to topical steroids, and should be used and applied in a different way. When using the two treatments, apply the emollient first. Then wait 10-15 minutes before applying a topical steroid. That is, the emollient should be allowed to absorb before a topical steroid is applied (the skin should be moist or slightly tacky but not slippery, when applying the steroid).
Are there any side-effects from topical steroids?
Short courses of topical steroids (less than four weeks) are usually safe and usually cause no problems. Problems may develop if topical steroids are used for long periods, or if short courses of stronger steroids are repeated often. The main concern is if strong steroids are used on a long-term basis. Side-effects from mild topical steroids are uncommon.
- Thinning of the skin has always been considered a common problem. However, recent research suggests that this mainly occurs when high-strength steroids are used under airtight dressings. In normal regular use skin thinning is unlikely and, if it does occur, it often reverses when the topical steroid is stopped.
- With long-term use of topical steroid the skin may develop permanent striae (like stretch marks), bruising, discolouration, or thin spidery blood vessels (telangiectasia).
- Topical steroids may trigger or worsen other skin disorders such as acne, rosacea and perioral dermatitis.
- Some topical steroid gets through the skin and into the bloodstream. The amount is usually small and usually causes no problems unless strong topical steroids are used regularly on large areas of the skin. The main concern is with children who need frequent courses of strong topical steroids. The steroid can have an effect on growth. Therefore, children who need repeated courses of strong topical steroids should have their growth monitored.
Occasionally, some people become sensitised (allergic) to an ingredient in a topical cream (such as a preservative). This can make the skin inflammation worse rather than better.
A leaflet comes with each topical steroid and gives a full list of possible side-effects.
Two common mistakes when using topical steroids
Some people use too little
A common mistake is to be too cautious about topical steroids. Some parents undertreat their children’s eczema because of an unfounded fear of topical steroids. They may not apply the steroid as often as prescribed, or at the strength needed to clear the flare-up. This may actually lead to using more steroid in the long-term, as the inflamed skin may never completely clear. So, you may end up applying a topical steroid on and off (perhaps every few days) for quite some time. The child may be distressed or uncomfortable for this period if the inflammation does not clear properly. A flare-up is more likely to clear fully if topical steroids are used correctly.
Some people use too much
Only use topical steroids for eczema as directed by your doctor. Some people continue to use topical steroids each day in the long term after the eczema has cleared to “keep the eczema away”. This is not normally needed. Some people, with severe eczema, may require continuous steroid treatment but this should be under the close supervision of a doctor. However, all people with eczema should use emollients (moisturisers) every day to help prevent further flare-ups of eczema.
Further help and information
National Eczema Society
Tel (Helpline): 0800 089 1122 Web: www.eczema.org
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