Skin Care World

Topical steroid preparations are divided up into four categories according to how strong or potent they are. The terms used are: mild, moderately potent, potent and very potent. It can be difficult to work out the potency of a product since a low percentage of steroid does not necessarily imply a less potent product. The potency of the steroid you are given will be based on several factors:

• Your age. Children are usually prescribed mild steroids although occasionally a stronger preparation may be required, depending on the severity of the eczema;
• Severity of the eczema. A mild or moderately potent steroid may be replaced by a stronger potency if the eczema flares up;
• Body site. Thick skin areas such as the feet and hands can be treated with potent preparations. For the face and genital areas mild and moderately potent preparations are commonly prescribed, a potent steroid will only be used for severe, unresponsive eczema in these areas, usually for a limited period. If the steroid is applied to the body folds or in areas covered by tight clothing this increases its potency so a milder preparation should be used;
• Size of the affected area. A weaker strength may be prescribed when a large area of skin requires treatment;
• Other treatments. If bandaging forms part of the treatment a weaker steroid may be chosen because bandaging increases the potency of the steroid.

Application

Steroid preparations should not be used to prevent eczema occurring, only to treat the symptoms. You will usually be instructed to apply a steroid twice a day although in some cases a doctor may recommend three times. Any further use of the steroid will not be of benefit in controlling the eczema and could be harmful to the skin on a long term basis. Some steroid preparations have now been developed that only need to be applied once a day to control eczema. This means that the amount of steroid used is reduced.

There are no standard rules regarding whether to apply a steroid preparation after or before using an emollient. Some people are happiest using an emollient first to prepare the skin, followed by the steroid. However, whichever order of care you choose it is important that you leave as long a period as practical, at least 15 minutes, between the two treatments.

Topical steroids should be applied sparingly as a thin smear. It can sometimes be difficult to judge how much steroid to use and there are now guides on the amount of treatment required to cover body areas that are affected by eczema. These have been based on the Finger Tip Dosing Unit (TFDU) which relates to 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 it comes out of an ordinary tube nozzle (see figure 1). Different parts of the body require different numbers of finger-tip units (FTU) of steroid used on them e.g. in an adult one arm will need 3 FTUs whilst a 4-year old child would require just over 1/2 of this amount i.e. 1FTU for an arm and hand (see figures 2 & 3). Adjustments will be required if the whole area is not covered by eczema. Further information of this kind is often provided in the leaflet supplied with your medication.

All steroids will be marked with a use-by-date and should not be used after the time stated. You will usually be given a set period of time in which to use the preparation. Any steroid that remains at the end of a treatment should not be passed on for use by anyone else. Repeated prescriptions are not generally advised in cases of eczema since the condition can alter and it is important that the doctor sees the skin to reassess the suitability of the treatment.

Are topical steroids a safe treatment for eczema?

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. All these factors will be taken into consideration when a prescription is given to treat eczema. Pregnant women should consult their doctor regarding the advisability of continued use of their usual topical steroid preparation.

If used over long periods of time topical steroids can thin the skin making it appear transparent, fragile and over-susceptible to bruising. Blood vessels may also become more prominent. With time the skin can become so badly damaged that it loses its elasticity so that ‘stretch marks’ develop. However, these effects usually only occur when potent steroids have been applied for a long time, either to the face or to covered parts of the body such as the flexures. Thinning can also occur when steroids are regularly applied under occlusion e.g. to the hands with plastic gloves or bags over and for this reason treatment of this type is limited to short periods of time under supervision of a doctor or nurse.

Hydrocortisone 1%, 0.5%, 0.1% or 0.05% is extremely unlikely to cause effects of this kind and can be used on the face and in young children. Be careful not to confuse with hydrocortisone butyrate which is a potent topical steroid.

Other possible side effects include increased hair growth of very fine hair and perioral dermatitis i.e. a spotty rash around the mouth.

It is important to bear in mind that these effects take several weeks to develop and will be avoided if potent preparations are limited in use and replaced by less potent preparations once they have brought a ‘flare up’ of the eczema under control.

There is also a risk from topical steroids being absorbed into the blood through the skin. Again the likelihood of this occurring is linked to the amount of steroid used and the age of the person involved. The main problem relating to absorption of steroids is a slowing down of growth in children by suppression of the adrenal gland. It is for this reason that strong steroids will only be prescribed for short periods of time for young children and if required over long periods only under the supervision of, and monitoring by, a hospital specialist.

If used over long periods of time treatment with potent topical steroids is unlikely to be stopped abruptly and people will be ‘stepped down’ through lower potency preparations before steroid treatment is finished altogether.

Allergy to the steroid itself or to the base of the preparation can occur. If the eczema gets worse after using a particular steroid let your doctor know.

Fear of side effects can make people under-treat their eczema by stopping a treatment too soon or not using the steroid they have been given. This can be detrimental to the overall management of the condition and may mean that a stronger preparation has to be used to bring the eczema under control again.

New formulations have recently been developed which have the added advantage of once-daily usage, but it remains to be seen if these are less likely to cause many of the side effects of older steroids. Ask your doctor for up-to-date details.

FURTHER INFORMATION

This fact sheet is one of a series provided as a service by the National Eczema Society to give up-to-date, practical help. More detailed information on this and other eczema-related subjects is available to members of the National Eczema Society. Membership of the Society costs just £20 per year.

Members receive a comprehensive information pack and copies of the Society’s quarterly journal, Exchange. They also have unlimited access to the Society’s Information Service. Membership of the National Eczema Society also offers people affected by eczema the opportunity to talk with others who share similar problems and experiences.