What are topical steroids?

Topical steroids (also known as topical corticosteroids) are immunosuppressant creams and
ointments that are used to treat inflammation (flare-ups) in eczema. They reduce redness
and make the skin less itchy and sore, helping it to heal. They have been used to treat and
control eczema flare-ups for over 50 years and are recommended in NHS guidance as a first-
line treatment for eczema. For some people with eczema, regular use of emollients (medical
moisturisers) is all that is needed to keep their condition under control. However, for most
people, topical steroids will need to be used for short treatment bursts, at the correct strength to match the person’s age, severity of eczema and body area, to bring an eczema flare-up under control.

When should topical steroids be used?

Topical steroids are mostly prescribed to treat eczema flares. You will usually be instructed to apply topical steroid for short bursts of treatment, and then stop or step down use when the eczema flare settles. If you are prescribed a milder steroid you will usually be told to stop after a burst of treatment, but if you are prescribed a stronger steroid, you may be instructed to ‘step down’ back to lower potency preparations as your eczema flare settles.

Sometimes people with more severe eczema whose eczema flares very frequently are prescribed
topical steroids to apply on two consecutive days a week on the areas where their eczema usually
flares. This is known as ‘weekend therapy’ and can help to prevent the almost continuous flare cycle, meaning that in the long run less topical steroid would be needed to control the eczema than if each flare were treated as it occurred.

How much should I apply?

It is important to use enough topical steroid, as using small amounts continuously often results in the topical steroid not working as well and perhaps more being used in the long term.

Topical steroids should be applied with clean hands in a thin layer so that the skin just glistens. It can sometimes be difficult to judge how much steroid to use – there are guidelines on the amount required to cover body areas that are affected by eczema. These are based on the Finger Tip Unit (FTU), which is the amount of cream or ointment that just covers the end of an adult finger from the tip to the crease of the first joint when squeezed from an ordinary tube nozzle. One FTU is enough to cover an area of skin the size of two adult hands with the fingers together.

Different parts of the body require different amounts of topical steroid. For example, in an adult, one arm will need 3 FTUs while a 4-year-old child will require 1 FTU for an arm and hand. Adjustments will be required if only a small part of the larger area is affected by eczema. Further information is often provided in the leaflet supplied with your treatment, and in our Topical steroids factsheet. Any unused steroid cream or ointment should be discarded. Wash your hands after applying steroids unless there is eczema on the fingers.

How do I know which potency of topical steroid I’m using?

In the UK, topical steroid preparations are divided into four categories according to how strong or potent they are. The terms used are ‘mild’, ‘moderately potent’, ‘potent’ and ‘very potent’. The potency of topical steroids is determined by the amount of vasoconstriction (narrowing of the blood vessels) they produce. It also relates to the degree to which the topical steroid inhibits inflammation, and its potential for causing side effects.

It can be difficult for the person with eczema or the parent of a child with eczema to work out the potency of a product, since the labelled percentage of steroid on the packaging does not relate to the potency and may sometimes imply a less potent product. The potency of the topical steroid may be stated in the patient information leaflet (PIL) inside the packaging.

One way of understanding the strength of different steroid preparations is to note that ‘moderately potent’ is twice as potent as hydrocortisone 1%; ‘potent’ is 10 times more potent; and ‘very potent’ 50 times more potent. If you are not sure of the potency of a steroid preparation, ask your pharmacist.

Are topical steroids safe?

Topical steroids, used appropriately and under supervision, are a safe and effective treatment for eczema. The likelihood of side effects occurring is directly related to the potency of the preparation, where it is being used, the condition of the skin on which it is used and the age of the person concerned. Pregnant women should consult a healthcare professional regarding the advisability of continued use of their usual topical steroid preparation. All these factors will be taken into consideration when a prescription is given to treat eczema.

If used over long periods of time, topical steroids can thin the skin, making it appear transparent, fragile and susceptible to bruising; blood vessels may become more prominent, and the skin can lose its elasticity, developing ‘stretch marks’. Other possible side effects include increased hair growth of very fine hair and perioral dermatitis (i.e. a spotty rash around the mouth). However, it should be stressed that these effects usually only occur when potent steroids have been applied for a long period of time, either to the face or to covered parts of the body such as the flexures.

Skin thinning can also occur when steroids have been applied under occlusion (e.g. under bandages or gloved hands). For these reasons, topical steroid use is limited to short periods of time under the supervision of a doctor or nurse.

For more information on topical steroids, please see our Topical steroids factsheet and an article from our magazine, Exchange, ‘How safe are topical corticosteroids?’ (2018)