Important aspects of prescribing information relevant to primary healthcare are covered in this section specifically for the drugs recommended in this CKS topic. For further information on contraindications, cautions, drug interactions, and adverse effects, see the electronic Medicines Compendium (eMC) (http://emc.medicines.org.uk), or the British National Formulary (BNF) (www.bnf.org).

• The potency of the topical corticosteroid prescribed depends on the severity of the dermatitis, the size of the area affected, the location of the dermatitis, and whether it is acute or chronic:
• For acute, severe, localized contact dermatitis on the body or limbs, prescribe a potent topical corticosteroid (e.g. betamethasone valerate 0.1%).
• For chronic or more widespread dermatitis (but less than 20% body surface area), potency may need to be reduced.
• In children, start treatment with a mildly potent topical corticosteroid (e.g. hydrocortisone 1%).
• For areas of thin skin (e.g. the face or genitals) and in flexures, prescribe a mildly potent topical corticosteroid.
• For areas of thick skin (e.g. palms or soles) and lichenified dermatitis, a potent topical corticosteroid will usually be needed, as penetration of topical corticosteroids is reduced, decreasing the effectiveness.
• The eyelids should be treated only with a mildly potent topical corticosteroid for a maximum of 5 days, taking care to avoid contact of the corticosteroid with the surface of the eye.
• Prescribe a topical corticosteroid in an appropriate formulation for the person and their condition:
• Ointments are recommended in preference to creams because they provide the strongest emollient effect.
• Creams may be preferred by some people, especially when used on visible areas, such as the face and hands:
• Creams are water-based and contain preservatives that can have irritant or allergen potential.
• Other formulations may be more suitable for specific areas of skin, such as the scalp, where liquids and foams will penetrate the hair better.

[Beck and Wilkinson, 2004; Beltrani et al, 2006]

• Table 1 shows the topical corticosteroid products available in the UK.

• Table 2 shows the amount of corticosteroid required to treat a flare of dermatitis for 1 week in an adult (about half of this is needed for a child). Usually, 100 grams is adequate.

• When used correctly, topical corticosteroids rarely cause serious adverse effects. The likelihood of adverse effects is directly related to the potency and amount of topical corticosteroids used — a thin layer should be applied once or twice a day, adjusting the potency to control symptoms.
• Systemic adverse effects are rare but include adrenal suppression that can result in symptoms of Cushing's syndrome and in children, growth retardation. Table 1 shows the safe weekly prescribing limit for topical corticosteroids to avoid systemic adverse effects. This is based on expert opinion, not data derived from controlled trials, and local adverse effects may occur at lower doses.
• Local adverse effects are more common.
• Transient burning or stinging is most common and may necessitate changing the product.
• Of more concern is skin atrophy, which is particularly common in the skin of the antecubital or popliteal fossae.
• Hypertrichosis, telangiectasia (especially on cheeks), acne, and steroid-induced contact dermatitis may also occur.

• Evidence on the safety of topical corticosteroids over the longer term is lacking, as most controlled studies have been performed over short time periods (typically 6 weeks or less). Therefore, CKS has largely based its recommendations on extrapolation of short trials, limited observational studies, clinical experience, and expert consensus, all of which are reflected in narrative reviews [Charman and Williams, 2003; DTB, 2003].

• Provide education on the correct use of topical corticosteroids.
• Advise the person to apply the corticosteroid in a thin layer to all the affected areas.
• Most products will be supplied with an information leaflet which will specify the number of finger-tip units needed to treat specific body areas. One finger-tip unit is the amount of ointment or cream expressed from a tube with a standard 5 mm diameter nozzle, applied from the distal crease to the tip of the index finger, and is sufficient to treat a skin area about twice that of the flat of the hand with the fingers together [MeReC, 1999].
• For acute episodes of contact dermatitis, advise the person to:
• Apply the topical corticosteroid no more than twice a day. For many people, once-daily application will be sufficient, but this can be increased if response is inadequate.
• Continue treatment for 48 hours after the dermatitis has cleared (if it has not improved after 2 weeks, the person should return for further advice).

Frequency of application

• The frequency of application of topical corticosteroids has been the subject of a National Institute for Health and Clinical Excellence Technology Appraisal that identified evidence from 10 randomized controlled trials (RCTs) and found that, overall, there was little difference in effectiveness between once-daily and more frequent application of topical corticosteroids, although a difference could not be ruled out [NICE, 2004]. Taking into account cost-effectiveness information, NICE recommended that topical corticosteroids should be prescribed 'for application only once or twice daily'.
• CKS recommends that, on a practical basis, most people should use topical corticosteroids once a day at first, and increase to twice a day only if they perceive that the condition is not responding adequately. Once-daily application has some potential advantages [Williams, 2007]:
• It may cause fewer adverse effects. Although this has not been tested by RCTs, it is a reasonable assumption, as the adverse effects of topical corticosteroids are known to be dose-dependent. Once-daily dosing may be particularly relevant for the control of chronic eczema.
• It is more convenient for the person. In turn, this may improve compliance.
• It is less expensive (although this may not be true for some products licensed for once daily application, e.g. Mometasone furoate).

• There is no evidence to guide the optimum dose and duration of oral corticosteroids in an acute episode of contact dermatitis. Some experts recommend prednisolone 0.5–1 mg/kg/day, given for 5–7 days and then tapered over 2–3 weeks (according to response) to prevent rebound dermatitis [Beltrani et al, 2006; Mark and Slavin, 2006; Jacob and Castanedo-Tardan, 2007].
• The frequent or prolonged use of systemic corticosteroids is associated with serious adverse effects, including growth retardation in children, diabetes mellitus, high blood pressure, and osteoporosis. However, these are unlikely to be a problem with a single, short course of prednisolone. Consider referral:
• If more than very occasional use is needed (e.g. more than one course in a year).
• For children younger than 16 years of age.
• Do not prescribe an oral corticosteroid if continued exposure to the allergen cannot be avoided.

• The choice of emollient should be determined by:
• The dryness of the skin.
• The type of skin to which the emollient is to be applied.
• The individual's preference, determined by the product's tolerability and convenience of use.
• Dryness of skin:
• Less to moderately dry skin is most acceptably treated with a cream.
• Moderately dry to very dry skin requires a higher intensity of treatment with an ointment to restore the skin to normal.
• Weeping dermatitis is best treated with a water-soluble cream, as ointments will tend to slide off, becoming unacceptably messy.
• The tolerability and convenience of a product can only be determined by a trial of treatment:
• Creams are generally better tolerated but will need to be applied more frequently and generously to have the same effect as a single application of ointment.
• The individual will need to balance the tolerability of a product against the convenience of its use and its effectiveness.
• More than one type of product may be required. Different products may be preferred at different times, depending on the intensity of treatment required and the area of skin to be treated (e.g. a cream may be preferable for application to the hands).
• Emollient soap substitutes are useful to avoid the drying effects of soaps and should be considered for all people with dermatitis. They are particularly useful for people who must wash or wet their hands frequently. The use of emollients as soap substitutes has been shown to reduce the incidence and prevalence of contact dermatitis [Lauharanta et al, 1991].
• Emollients containing active ingredients are not generally recommended, but may be useful in some people (although they increase the risk of skin reactions). Products containing:
• Lauromacrogols are reputed to relieve itch.
• Urea may improve skin hydration and have a limited role in the treatment of skin with heavy scaling.
• Antiseptics (e.g. benzalkonium chloride) have a limited role in protecting skin which is prone to infection.
• For a list of the emollient products available in the UK, see Table 1.

• No evidence from controlled trials supports the use of one emollient over another; therefore, recommendations are based on the known physiological properties of emollients and pragmatic considerations:
• Emollients with high lipid contents are thought to restore the skin barrier more effectively, and more rapidly, than those with lower lipid contents [Dermatology UK, 2007].
• The person's preference is essential when selecting an emollient. The National Institute for Health and Clinical Excellence points out that, in atopic eczema, proprietary products are generally preferred (at least by children) to non-proprietary products, and therefore non-proprietary products are not suitable as first-line treatment. They also state that as proprietary products tend to be similar in cost, the person should be prescribed the emollient of their choice [National Collaborating Centre for Women's and Children's Health, 2007].
• In general, the evidence to support the use of active ingredients in emollients is limited. Therefore, if used, these products should be trialled on an individual basis:
• One randomized controlled trial (RCT, n = 80) was identified by a systematic review [Hoare et al, 2000] that found an emollient containing urea was more effective than the vehicle alone in the treatment of atopic eczema.
• Evidence from several small RCTs using emollients combined with an antiseptic were of poor quality and subject to bias.
• CKS did not identify any trials that used emollients containing lauromacrogols as an intervention.

• The most common adverse effect of emollients is irritation caused by sensitivity of the skin to an ingredient in the emollient.
• Skin reactions are usually irritant rather than allergic. The skin shows an immediate and dose-dependent inflammatory response:
• If a skin reaction occurs, stop use of the product and use a different emollient. If the person has had previous skin reactions to emollients, it may be prudent to test a small quantity before widespread application.
• Ingredients commonly implicated in skin reactions to emollients include perfumes and preservatives.
• If sensitivity to emollients is a known problem, the chance of a further reaction is reduced by prescribing a cream with few added ingredients or prescribing an ointment (these do not require preservatives and generally have fewer excipients).
• If the person has reacted to several products, consider referral for patch testing to confirm or exclude contact allergy and to identify the responsible allergen(s).
• The occlusive effect of ointments can cause folliculitis:
• Advise the person to apply the ointment in the direction of hair growth.
• If folliculitis occurs, stop use of the ointment (consider switching to a cream) and use an antibiotic if necessary.
• Emollients can present physical hazards:
• Paraffin-containing products are highly flammable and should not be used near naked flames or whilst smoking.
• Bath emollients can pose a slip hazard.
• Table 1 shows ingredients used in emollients that have been reported to cause sensitization reactions in skin.

• Advise the person to use the emollient liberally and frequently:
• The frequency of application will vary depending on the person's condition and circumstances, but for very dry skin, application of an emollient every 2–3 hours should be considered appropriate.
• To facilitate frequent application, the person should consider keeping separate packs of emollients at work or school.
• It may be more convenient to use better tolerated products (creams and lotions) during the day and ointments at night.
• Advise the person about the effective application of emollients. Emollients should be applied by smoothing them into the skin along the line of hair growth, rather than rubbing them in:
• Creams and lotions are better for red, inflamed areas of skin.
• Ointments are suitable for areas of dry skin that are not inflamed.