Topical corticosteroids are used for the treatment of inflammatory conditions of the skin (other than those arising from an infection) and are safe if used correctly. They are effective in conditions such as eczema and psoriasis.
Topical corticosteroids only suppress the inflammatory reaction during use; they will not cure the condition and the skin problem may get worse once the use of topical corticosteroids stops. This is called a rebound effect. They are generally used to relieve symptoms and suppress signs of the disorder when other measures such as emollients are ineffective.
Topical corticosteroids are categorised in four strength categories:
- very potent.
The strength chosen is prescribed by doctors depending upon the patient and the extent and severity of the condition.
The risk of side effects runs parallel with the strength of the steroid and the duration of therapy. The face, genitals and skin fold areas will absorb more steroids than other areas. If you use a steroid under a bandage (making it occlusive) or via a plaster it will also have the same effect. Side effects on the skin may be apparent within two weeks of use.
Potent and very potent steroids should be carefully monitored and limited to a few weeks of use, after which a milder steroid should be substituted if possible.
Pulsing is a term used when a steroid is used for four weeks, with four weeks’ rest or more if the skin is clear. This use of topical steroids allows the skin to recover between courses of treatment and patients should be reviewed every three months. Only mildly and moderately potent steroids should be used in children to avoid potential growth retardation and long-lasting cosmetic disfiguration; if they have severe psoriasis a dermatologist might give different instructions. If allergic contact dermatitis occurs with topical steroids, then patch testing is required and patients should be switched to another steroid in the same potency group. If tachyphylaxis (decrease in the response to a drug) occurs then it is best to change to another product using a different molecule.
Systemic or very potent topical corticosteroids should be avoided or given only under specialist supervision in psoriasis (such as palmar plantar psoriasis) because, although they may suppress the psoriasis in the short term, relapse or vigorous rebound occurs on withdrawal (sometimes precipitating severe pustular psoriasis). These can be combined with another topical therapy that can be continued on the four weeks’ rest period, for example a vitamin D preparation.
In the case of scalp psoriasis it is reasonable to use a more potent corticosteroid. Unfortunately there are only potent or very potent corticosteroid products, such as gels, foams, shampoos or lotions. Again, pulsing can be effective once you have control. It should be prescribed as a once-a-day application, although in severe cases a dermatologist may advise a twice-a-day application in the short term. If the scalp is very scaly then your dermatologist will be able to show you how to use a suitable moisturiser. Skin infections are not that common in psoriasis, but can be found between two skin folds that get moist or rub, and antibacterial agents can be combined with steroid preparations with good effect. However, the antibiotic can act as an allergen in some patients. Topical therapies are ideal for localised problems, whereas oral antibiotics will be prescribed for more widespread infection. Topical antibiotic combination preparations should only be used for two weeks, to prevent bacterial resistance and reduce adverse effects so pulsed treatment can be used.
For further information on different strengths follow the links below