BNF for Children 2011-2012

BNFC 2011–2012 13.5.2 Preparations for psoriasis 567be stopped or the concentration reduced; if it is tolerated,its effects should be assessed after 4 to 6 weeksand treatment continued if it is effective.Widespread unstable psoriasis of erythrodermic or generalisedpustular type requires urgent specialist assessment.Initial topical treatment should be limited to usingemollients frequently and generously. More localisedacute or subacute inflammatory psoriasis with hot,spreading or itchy lesions, should be treated topicallywith emollients or with a corticosteroid of moderatepotency.Scalp psoriasis is usually scaly, and the scale may bethick and adherent. This requires softening with anemollient ointment, cream, or oil and usually combinedwith salicylic acid as a keratolytic.Some preparations for psoriasis affecting the scalpcombine salicylic acid with coal tar or sulphur. Thepreparation should be applied generously and left on forat least an hour, often more conveniently overnight,before washing it off. If a corticosteroid lotion or gel isrequired (e.g. for itch), it can be used in the morning.Calcipotriol and tacalcitol are analogues of vitamin Dthat affect cell division and differentiation. Calcitriol isan active form of vitamin D. Vitamin D and its analoguesare used as first-line treatment for plaque psoriasis; theydo not smell or stain and they may be more acceptablethan tar or dithranol products. Of the vitamin D analogues,tacalcitol and calcitriol are less likely to irritate.Coal tar has anti-inflammatory properties that are usefulin chronic plaque psoriasis; it also has antiscalingproperties. Contact of coal tar products with normalskin is not normally harmful and preparations containingcoal tar can be used for widespread small lesions;however, irritation, contact allergy, and sterile folliculitiscan occur. Leave-on preparations that remain in contactwith the skin, such as creams or ointments, containingup to 6% coal tar may be used on children 1 month to 2years; leave-on preparations containing coal tar 10%may be used on children over 2 years with more severepsoriasis. Tar baths and tar shampoos (see section 13.9)may also be helpful.Dithranol is effective for chronic plaque psoriasis. Itsmajor disadvantages are irritation (for which individualsusceptibility varies) and staining of skin and of clothing.It should be applied to chronic extensor plaques only,carefully avoiding normal skin. Dithranol is not generallysuitable for widespread small lesions nor should itbe used in the flexures or on the face. Treatment shouldbe started with a low concentration such as dithranol0.1%, and the strength increased gradually every fewdays up to 3%, according to tolerance. Proprietarypreparations are more suitable for home use; they areusually washed off after 20–30 minutes (‘short contact’technique). Specialist nurses may apply intensive treatmentwith dithranol paste which is covered bystockinette dressings and usually retained overnight.Dithranol should be discontinued if even a low concentrationcauses acute inflammation; continued use canresult in the psoriasis becoming unstable. When applyingdithranol, hands should be protected by gloves orthey should be washed thoroughly afterwards.A topical corticosteroid (section 13.4) is not generallysuitable as the sole treatment of extensive chronicplaque psoriasis; any early improvement is not usuallymaintained and there is a risk of the condition deterioratingor of precipitating an unstable form of psoriasis(e.g. erythrodermic psoriasis or generalised pustularpsoriasis). However, it may be appropriate to treat psoriasisin specific sites such as the face and flexuresusually with a mild corticosteroid, and psoriasis of thescalp, palms and soles with a potent corticosteroid.Combining the use of a corticosteroid with anotherspecific topical treatment may be beneficial in chronicplaque psoriasis; the drugs may be used separately atdifferent times of the day or used together in a singleformulation. Eczema co-existing with psoriasis may betreated with a corticosteroid, or coal tar, or both. Systemicor potent topical corticosteroids should beavoided or used only under specialist supervision;although corticosteroids may suppress psoriasis in theshort term, relapse or vigorous rebound occurs onwithdrawal.Phototherapy Phototherapy is available in specialistcentres under the supervision of a dermatologist. Narrowband ultraviolet B (UVB) radiation is usually effectivefor chronic stable psoriasis and for guttate psoriasis.It can be considered for children with moderately severepsoriasis in whom topical treatment has failed, but itmay irritate inflammatory psoriasis. The use of phototherapyand photochemotherapy in children is limitedby concerns over carcinogenicity and premature ageing.Photochemotherapy combining long-wave ultravioletA radiation with a psoralen (PUVA) is available inspecialist centres under the supervision of a dermatologist.The psoralen, which enhances the effect of irradiation,is administered either by mouth or topically.PUVA is effective in most forms of psoriasis, includingthe localised palmoplantar pustular psoriasis. Earlyadverse effects include phototoxicity and pruritus. Highercumulative doses exaggerate skin ageing, increasethe risk of dysplastic and neoplastic skin lesions especiallysquamous cancer, and pose a theoretical risk ofcataracts.Phototherapy combined with coal tar, dithranol, topicalvitamin D or vitamin D analogues, or oral acitretin,allows reduction of the cumulative dose of phototherapyrequired to treat psoriasis.Systemic treatment Systemic treatment is requiredfor severe, resistant, unstable or complicated forms ofpsoriasis, and it should be initiated only under specialistsupervision. Systemic drugs for psoriasis include acitretinand drugs that affect the immune response (section13.5.3).Acitretin, a metabolite of etretinate, is a retinoid (vitaminA derivative); it is prescribed by specialists. Themain indication of acitretin is severe psoriasis resistantto other forms of therapy. It is also used in disorders ofkeratinisation such as severe Darier’s disease (keratosisfollicularis), and some forms of ichthyosis. Although aminority of cases of psoriasis respond well to acitretinalone, it is only moderately effective in many cases;adverse effects are a limiting factor. A therapeutic effectoccurs after 2 to 4 weeks and the maximum benefit after4 to 6 weeks or longer. Continuous treatment for longerthan 6 months is not usually necessary in psoriasis.However, some patients, particularly those with severeichthyosis, may benefit from longer treatment, providedthat the lowest effective dose is used, patients aremonitored carefully for adverse effects, and the needfor treatment is reviewed regularly. Topical preparationscontaining keratolytics should normally be stoppedbefore administration of acitretin. Liberal use of emol-13 Skin