Corticosteroids (topical) - How to use topical corticosteroids

Unless instructed otherwise by your doctor, follow the directions that come with your topical corticosteroid medication. This will give details of how much to apply and how often.

Most people only need to use the medication once or twice a day for a week or two, although occasionally your doctor may suggest using it less frequently over a longer period of time.

The medication should only be applied to affected areas of skin. Gently smooth it into your skin in the direction the hair grows.

Fingertip units (FTUs)

Sometimes, the amount of medication you are advised to use will be given in fingertip units (FTUs).

An FTU is the amount of medication needed to squeeze a line from the tip of an adult finger to the first crease of the finger.

An FTU is about 500mg. It should be enough to treat an area of skin double the size of the flat of your hand with your fingers together.

The recommended dosage in terms of FTUs will depend on what part of the body is being treated. This is because the skin is thinner in certain parts of the body and more sensitive to the effects of corticosteroids.

For adults, the recommended FTUs to be applied in one single dose are:

0.5 FTU for genitalia
1 FTU for hands, elbows and knees
1.5 FTUs for the feet, including the soles
2.5 FTUs for the face and neck
3 FTUs for the scalp
4 FTUs for a hand and arm together, or the buttocks
8 FTUs for the legs and front or back of the trunk (the main section of the body, excluding the arms, legs and head)

For children, the recommended FTUs will depend on their age. Your GP can advise you on this.

Using topical corticosteroids and emollients

Some people using topical corticosteroids also need to use emollients regularly. These are creams and lotions designed to prevent the skin becoming dry, scaly and itchy.

If you are using both topical corticosteroids and emollients, you should apply the emollient first. Then wait about 30 minutes before applying the topical corticosteroid.