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1. Provide a practical approach to the management of psoriasis in the pediatric primary care setting.

2. Review the proper selection and utilization of topical agents for the management of pediatric psoriasis.

3. Recognize moderate-to-severe psoriasis and when referral to a dermatologist for advanced man-agement is indicated.

Tina Bhutani, MD, is Clinical Research

Fellow, UCSF Psoriasis and Skin Treatment

Center, UCSF Department of Dermatology.

Faranak Kamangar, BSc, is Clinical Research

Associate, UCSF Psoriasis and Skin Treatment

Center UCSF Department of Dermatology.

Kelly M. Cordoro, MD, is Assistant Professor

of Clinical Dermatology and Pediatrics, Uni-

versity of California, San Francisco. Address correspondence to: Kelly M. Cor-

doro, MD, University of California, San Fran-cisco; fax: 415-353-7478; email: cordorok@derm.ucsf.edu.

Dr. Bhutani and Ms. Kamangar have dis-closed no relevant financial relationships. Dr. Cordoro has disclosed the following relevant financial relationships: consulting fees, Topaz Pharmaceuticals.

doi: 10.3928/00904481-20111209-08

EDUCATIONAL OBJECTIVESC M E

Management of Pediatric Psoriasis Tina Bhutani, MD; Faranak Kamangar, BSc; and Kelly M. Cordoro, MD

Psoriasis is a chronic inflamma-tory disease of the skin, nails, and joints. Overall prevalence

in the US is 2.5%.1-3 Among children aged 0 to 18 years, prevalence is 1% and incidence is 40.8 per 100,000.4

More than one-third of patients pres-ent before age 20.5-9

The pattern of psoriasis presenta-tion in children can vary from what is classically observed in adults. Children have increased involvement of the face and anogenital regions, and pruritus is common.10 Plaque-type psoriasis is most common (73.7%)4 and presents as erythematous plaques with silvery-white scales typically involving the scalp, postauricular region (Figure 1a, see page e2), elbows, knees, umbilicus, and but-tocks (Figure 1b, see page e2).

Guttate psoriasis is the next most common type (13.7%);4 it is composed of few to numerous small (less than 1 cm), drop-like erythematous scaly pap-ules (Figure 1c, see page e2). Guttate psoriasis has a documented association with pharyngeal — and less commonly — perianal, streptococcal infection.11

Other common types are inverse psoriasis, involving the skin folds and flexures (neck, axillae, groin), and psoriasis in the anogenital area (diaper or “napkin” psoriasis). Diaper psoria-sis is especially common in children younger than 2 years of age and pres-ents as bright- to dull-red smooth or slightly scaly erythema in the diaper area, which may be accompanied by more typical psoriasis in other loca-tions (Figure 1d, see page e2).

Pustular and erythrodermic psoria-sis are uncommon subtypes in young

children10 but, when present, are typi-cally accompanied by systemic signs, including fever, chills, malaise, and subsequent dehydration and toxicity. Nail involvement such as pitting, ony-cholysis, and subungual debri can oc-cur with all types of psoriasis and can serve as a diagnostic clue (Figure 1e, see page e2).

The differential diagnosis for pso-riasis in children depends on the site of involvement. Scalp psoriasis pres-ents with discrete or confluent red patches with silvery scale. The scale may become very thick and mat the hair down in clusters. This is referred to as pityriasis amiantacea (Figure 1a, see page e2). The differential for scalp psoriasis includes: seborrheic derma-titis in infants and adolescents; atopic dermatitis (usually accompanied by other signs, symptoms, or a family history of atopy); and tinea capitis, which should be ruled out with a fun-gal culture.

Plaque and guttate psoriasis may be confused with nummular atopic dermatitis, a form of atopic dermatitis presenting with coin-shaped lesions. This also is typically accompanied by a personal or family history of atopy, and pityriasis rosea, a viral exanthem that follows Langer’s lines on the skin and thus is distributed in the classic “Christmas tree” pattern on the trunk and proximal extremities. Diaper pso-

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riasis must be differentiated from ir-ritant diaper dermatitis (which spares the folds) or candidal diaper dermatitis (“beefy” red plaques with characteris-tic satellite papules and pustules).12

ENVIRONMENTAL TRIGGERS A thorough history and physical

should be performed to identify poten-tial disease triggers. These include trau-ma (Koebner phenomenon), infections (especially pharyngeal and perianal group A beta-hemolytic streptococci and viruses including HIV), drugs (particu-larly recent oral steroid withdrawal), and physical or psychological stress.10

COMORBIDITIES Psoriasis is a chronic inflamma-

tory disease that may not be limited to the skin. Studies in adults have demonstrated an association between psoriasis and metabolic syndrome (hypertension, obesity, dyslipidemia, and hyperglycemia)12 and increased

cardiovascular risk. Psoriasis is also associated with increased rates of depression and decreased quality of life.13 Comorbidities in the pediatric population are less well defined, but data are emerging linking psoriasis to obesity and depression in children.14

Psoriatic arthritis in children is well documented, with a prevalence rang-ing from 5% to 40%.10,15 Onset age of psoriatic arthritis in children is usually between 9 and 12 years. Severe nail and digital disease is a clinical predic-tor of joint disease.16 However, cor-relation between the severity of skin disease and arthritis is usually poor.15

Since the true risk in this popula-tion is insufficiently investigated, whether pediatricians and dermatolo-gists should screen youths with psori-asis for the presence of comorbid con-ditions remains to be established. A reasonable approach is a detailed his-tory and physical examination, with directed investigations performed on

an individual basis. Counseling for patients with severe psoriasis is ap-propriate, since adult and preliminary pediatric data show that the risk for comorbidities, especially obesity, hy-pertriglyceridemia, and hyperglyce-mia, increases with disease severity.17

TREATMENT Topical Therapy

Available topical treatment ve-hicles include creams, ointments, foams, gels, lotions, liquid solutions, sprays, oils, and drug-impregnated tapes. Thicker vehicles such as oint-ments (usually petrolatum) are more occlusive and therefore often more effective than creams and lotions. Choice of vehicle is based on the lo-cation of the psoriasis and patient preference. Plaques on the extremities call for ointments or creams, where-as hair-bearing sites (scalp) require thinner preparations such as liquids, gels, lotions, sprays, oils, or foams.18

Figure 1. (a) scalp psoriasis; (b) typical plaque psoriasis; (c) guttate psoriasis; (d) diaper psoriasis; (e) nail psoriasis (pits); (f ) adolescent with atrophy and striae after using a highly potent topical steroid (clobetasol) twice daily for 6 months. Source: a-e, Cordoro KM; f, Sugarman J. Reprinted with permission.

a b c

d e f

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Twice-daily application is required for maximum effect of most topical medi-cations. The traditional dogma that ointments are more effective must be reconciled with patient preference to select vehicles that the patient will ac-tually apply. Adolescents often object to greasy ointments on the body and prefer creams, lotions, or foams. An ef-fective compromise is to prescribe cos-metically acceptable vehicles for day-time use and reserve oils and ointments for nighttime use.

CorticosteroidsTopical corticosteroids (TCS) are the

first-line agents for treatment of psoria-sis in all age groups and all body sites. They are anti-inflammatory, anti-prolif-erative, and reduce erythema, scaling, and pruritus.19 TCS range in potency from the very weak Class VII to high-ly potent Class I agents.20 In general, psoriasis on sensitive or occluded sites (face, neck, genitalia/diaper area, folds, flexures including axillae and proxi-mal thighs) call for lower potencies, whereas thicker psoriasis on the trunk, extremities, palms, soles, and scalp re-quire higher potencies. The thin skin of the case and inguinal folds is also more at risk for irritation from tazarotene and calcipotriene. Figure 2 provides a quick reference for the potency of TCS that may be used for various body sites.

If higher potency agents are re-quired for thicker plaques in high-risk sites such as the diaper area, their use should be limited to short bursts of daily application only until the plaques thin down, followed by reduction of potency, frequency, or both. An of-ten under-appreciated area of concern for the risk of atrophy and striae from long-term use of high-potency topical steroids is the proximal medial aspect of the upper and lower extremities, especially in rapidly growing, peri-pubertal patients (Figure 1f, see page e2). Extremely potent agents should be

avoided or used sparingly in infants. To decrease the risk of potential ad-verse effects, such as cutaneous atro-phy, combine or rotate topical steroids with steroid-sparing alternatives, such as vitamin D analogues, coal tar/liquor carbonis detergens (LCD), anthralin, and topical calcineurin inhibitors.

Infants have a high ratio of body surface area to mass, thus widespread application of TCS may result in sys-temic absorption.21 Close supervision and use of combination and rotational therapies will enhance efficacy and minimize the risk of side effects of TCS, such as skin atrophy, striae, tel-angiectasia, and adrenal suppression. A recent study examined the atropho-genic potential of TCS used for in-flammatory skin diseases in children.22 The researchers concluded that, when used appropriately, TCS do not cause skin atrophy.22 Their data provide evi-dence that the true risk of “thinning the skin” from the routine use of topi-cal steroids in children is far less than previously thought; however, caution is still advised and patients using topi-cal corticosteroids should be moni-tored routinely for beneficial as well as adverse effects.

There are a multitude of TCS formu-lations and potencies (see Table, page e4). For practical purposes, start with a short list of at least one generic medi-cation from each of the potency class-es and their available formulations. For example: low potency desonide is available in an ointment, cream, lotion, gel, and foam; mid-potency triam-cinolone acetonide is available as an ointment, cream, lotion, solution, and spray; and high-potency clobetasol propionate is available as an ointment, cream, lotion, solution, foam, spray, and shampoo. This clinically useful toolbox of topical corticosteroids will aid in developing a site- and severity-based treatment plan. The patient/fam-ily can participate in the care plan by selecting treatment vehicle.

Vitamin D AnaloguesCalcipotriene (calcipotriol in Europe

and Canada) and calcitriol are vitamin D3 analogues that play a primary role in the treatment of childhood and adult psoriasis. In the US, calcipotriene is available in an ointment, cream, and solution; calcitriol is available in an ointment. They are efficient non-ste-roidal alternatives for monotherapy or

Figure 2. Guide to site-based topical therapy for psoriasis. Source: Cordoro KM. Reprinted with permission.

Face/Anogenital:· Low-potency TCS· TCI· 3% LCD (in emollient or 1% HC)· Emollient

Eyelids:· 1% HC ointment or TCI· Emollient

Palms/Soles:· Mid- to high-potency TCS· 5% to 20% LCD in TCS· Salicylic acid (>6 y/o)· Urea 10% to 40%· Tazarotene· Calcipotriene

TCS: topical corticosteroidsHC: hydrocortisoneLCD: liquor carbonis detergensKeratolytics: salicylic or lactic acid; urea 10% to 40%

Nails: · Tazarotene· TCI (especially for pustular variants)· Calcipotriene· TCS (beware of digital atrophy)· Keratolytics prn

Trunk/Extremities: · Low- to high-potency TCS· Calcipotriene· 5% to 20% LCD in low-mid TCS· Tazarotene (thick plaques)· Keratolytics prn

Scalp: · Low- to high-potency TCS or shampoo· Calcipotriene solution· Tar/LCD lotion, foam, or shampoo· Keratolytics (salicylic acid gel or shampoo; lactic acid, urea)· Anthralin

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in combination with topical steroids.23 Regimens combining vitamin D ana-logues and topical steroids are well tol-erated, steroid-sparing, and synergistic in action.24

Calcipotriene ointment has docu-mented efficacy, tolerability, and safety in children with psoriasis. It can be used as monotherapy in very mild cases with thin patches and plaques or in combina-tion with other topical agents for thicker or more severe disease. Local irritation is the most common side effect.25

Adverse effects on systemic calci-um homeostasis in adult psoriasis pa-tients have been evaluated and are re-lated to dose per unit of body weight. Though no formal guidelines exist for children, use of up to 45 g/m2/week of calcipotriene in children does not seem to influence serum ionized calci-um levels. Calcitriol ointment has also been shown to be effective and safe in children, with complete clearing of treated plaques after 4 weeks of treat-ment.26 Calcitriol ointment is report-

edly less irritating than calcipotriene ointment when used in sensitive areas such as flexures.27

Coal Tar and LCDTar is a safe, effective, steroid-spar-

ing treatment for childhood psoriasis. Crude coal tar has antipsoriatic, anti-seborrheic, antipruritic, and keratolytic effects.28 The mechanism of action is largely unknown, but enzyme inhibi-tion, antimitotic actions, and suppres-sion of DNA synthesis have been iden-

TABLE.

Commonly Used Topical Agents for Pediatric Psoriasis*

Agent Available Concentrations Available Vehicles

Low-potency topical corticosteroids

Desonide

Used for: sensitive areas (face, axillae, groin)• 0.05%

• Ointment

• Cream

• Lotion

• Gel

• Foam

Mid-potency topical corticosteroids

Triamcinolone acetonide

• 0.025%

• 0.1%

• 0.5%

• Ointment

• Cream

• Lotion

• Solution

High-potency topical corticosteroids

Clobetasol propionate

Limit to short bursts if used in high-risk areas (axillae, groin); then decrease potency

• 0.05%

• Ointment

• Cream

• Solution

• Gel

• Foam

• Spray

• Shampoo

Vitamin D analogue

Calcipotriene

Used in combination with topical corticosteroids for steroid-sparing effect

• 0.005%• Cream

• Solution (scalp)

Topical retinoid Tazarotene• 0.05%

• 0.1%• Gel

Coal tar/liquor carbons detergens (LCD)

Anti-inflammatory and keratolytic; can be compounded with corticosteroids, emollients, lactic and salicylic acids (eg, 5% LCD in 0.1% triamcinolone ointment)

• 20% LCD

• 2% crude coal tar (CCT)

• 5% CCT

• 10% CCT

Can be compounded in:

• Petrolatum

• Aquaphor

• Nutraderm lotion

• Cetaphil cream

2% available OTC as foam

*Not a comprehensive summary. Source: Cordoro KM. Reprinted with permission.

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tified.29 Tar is supplied in a variety of topical formulations and shampoos and can be used alone or compounded with corticosteroids, emollients, or lactic and salicylic acids. Coal tar is black and therefore may stain clothing, linens, and skin, potentially resulting in de-creased compliance. LCD is a modified coal tar with a cream to yellowish color that has largely replaced crude coal tar in the outpatient setting because of its cosmetic acceptability.30

LCD can be compounded in an ointment, cream, or solution vehicle in concentrations from 0.5% to 20%. The best use of tar is as a keratolytic (in-duces sloughing of scale), anti-inflam-matory agent on very thick plaques of psoriasis on the extremities, trunk, palms, soles, and scalp. Side effects of tar may include folliculitis, irritation, and photosensitivity. Tar should not be used on pustular or erythrodermic pso-riasis. There is no definitive evidence of increased risk for skin cancer above the baseline incidence for the general population from the use of therapeutic tar.31-33 Tar-based agents create photo-sensitivity and should be avoided on the face.

TazaroteneTazarotene is a third-generation

topical retinoid used to treat plaque psoriasis and moderate to severe acne vulgaris. Similar to other retinoids, tazarotene restores normal epidermal differentiation and proliferation and reduces inflammation.34 Tazarotene is neither sensitizing nor phototoxic35 but dose-related skin irritation often necessitates the use of topical steroids applied at the same or different time of day.36 Supplied as a cream or gel in 0.05% and 0.1% concentrations, taz-arotene should be limited to thicker plaques on nonintertriginous sites. Ir-ritation can be minimized by starting with 0.05% cream applied for 10 to 60 minutes per day, then washed off (short

contact therapy), or applying on alter-nate days or once weekly. Tazarotene is also effective for nail psoriasis.37,38 Tazarotene is a pregnancy category X agent in the US.

Topical Calcineurin InhibitorsTacrolimus and pimecrolimus are

non-steroidal immunomodulating mac-rolactams that inhibit IL-2 produc-tion and T-cell activation and pro-liferation.39 Both topical calcineurin inhibitors (TCI) are FDA-approved for second-line intermittent treatment of atopic dermatitis in patients aged 2 years and older (pimecrolimus and tacrolimus 0.03%) and 15 years and older (tacrolimus 0.1%). TCIs are used as steroid-sparing options in combina-tion or rotation with other topicals for psoriasis at high-risk sites for adverse effects of long-term topical steroid use (face, eyelids, flexures, fingertips/nails, anogenital region). Stinging or burning may occur when TCIs are ap-plied to fissured plaques or thin skin such as the eyelids. TCIs have not been proven unequivocally effective for thick plaque psoriasis on the elbows, knees, or trunk.

AnthralinAnthralin (dithranol) is a potent

anti-inflammatory and antiprolifera-tive agent.40 It is a synthetic version of chrysarobin, a natural substance derived from the araroba tree of South America, which has been used to treat psoriasis for nearly 100 years.41 Neg-ligible systemic absorption is respon-sible for anthralin’s excellent safety profile. Its use is limited because of the potential for staining and irritation with prolonged skin contact times. However, short contact and “min-utes” therapy are popular alternatives (increasing concentrations — 0.1% to 3% — dithranol applied to the skin and left in place for 10 to 30 minutes daily until slight irritation develops,

then maintain the same dose/time until clear).42 Lower concentrations or short-er contact time should be used on more sensitive sites such as anogenital skin.

Salicylic Acid, Lactic Acid, UreaKeratolytics are peeling agents used

to debulk thick plaques of psoriasis and are used in combination regimens with anti-inflammatory topicals such as TCS and vitamin D analogues. Salicylic acid, available over-the-counter (OTC) as a shampoo and by prescription as a 6% gel, is a useful adjunctive kerato-lytic for thick, localized plaques on the scalp, palms, and soles. It should be avoided in infants because of the risk for percutaneous salicylism.43 Lactic acid and urea are also effective kerato-lytics available OTC and by prescrip-tion as creams, lotions, and ointments.

PHOTOTHERAPY AND SYSTEMIC THERAPY

Although most cases of psoria-sis can be managed adequately with topical therapies, a subset of children present with severe or rapidly evolv-ing disease that may warrant the use of systemic or phototherapy. Photo-therapy is an effective treatment for carefully selected patients with diffuse guttate or plaque psoriasis or focal de-bilitating palmoplantar psoriasis.

Three main types of therapeutic light options exist: broadband UVB; narrowband UVB; and UVA. Narrow-band UVB is often selected for treat-ing children because of its ease of use and safety.

Phototherapy is administered in a physician’s office or phototherapy center and rarely via home photothera-py units. Short-term adverse reactions include burn and itch, while potential long-term risks include photodamage and cutaneous carcinogenesis.44,45

Severe or refractory plaque, pus-tular, or erythrodermic psoriasis and psoriatic arthropathy require systemic

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therapy. The three most commonly used systemic treatments for psoriasis in children are: acitretin, a non-immu-nosuppressing systemic retinoid; and the immunosuppressants methotrexate and cyclosporine. Because they have not undergone the scrutiny of random-ized controlled trials in this population, none are FDA-labeled for psoriasis in children. Accumulated data regard-ing the utility, benefits, and risks of these agents for treatment of psoriasis derives largely from long-term use in children with other disorders such as ichthyoses (acitretin), juvenile rheu-matoid arthritis (methotrexate), and organ transplantation (cyclosporine). There are vast amounts of anecdotal data regarding the use of these medi-cations in pediatric psoriasis; however, formalized treatment and monitoring guidelines do not yet exist. Patient se-lection is critical and requires expert dermatologic consultation.

Targeted therapy, rather than gener-alized immunosuppression, represents the newest direction in treatment and is accomplished by use of biologic mol-ecules. Tumor necrosis factor alpha-inhibitors (etanercept, adalimumab, and infliximab) are the most commonly used. Of all the currently available bio-logics, etanercept has the most signifi-cant published literature to substantiate recommendations for its use in the pe-diatric psoriasis population.46 Although biologics appear to be generally safe and effective, long-term data for psoria-sis are lacking; serious adverse events, including opportunistic infections, have been reported. Careful consideration of the risk-benefit ratio for individual pa-tients is required when deciding wheth-er to use this class of medications, which is very expensive.

CONCLUSIONManaging children with psoriasis

can be challenging due to the lack of approved therapies and compliance is-

sues. In contrast to adults with psoria-sis, little is known about the potential comorbidities of pediatric psoriasis. Given the potential effect of this dis-ease on overall physical and emotion-al well-being, these patients require vigilant monitoring. Although a subset of children present with severe, rap-idly evolving disease that requires sys-temic or phototherapy, most cases are mild, adequately managed with topical preparations. In patients with severe or refractory disease, or for psoriasis ac-companied by comorbidities such as obesity or arthritis, timely referral for dermatologic consultation may lessen the potential effect of psoriasis on pa-tients and families.

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40. Nghiem P, Pearson G, Langley RG. Tacro-limus and pimecrolimus: from clever pro-

karyotes to inhibiting calcineurin and treat-ing atopic dermatitis. J Am Acad Dermatol. 2002;46(2):228-241.

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