Palmoplantar—The palms and soles have a thicker epidermal layer than other areas of the body. As a result, class 1 corticosteroids can be used for palmoplantar psoriasis for more than 4 weeks with vigilant monitoring for adverse effects such as skin atrophy, tachyphylaxis, or tinea infection. Tazarotene also has been shown to be helpful in treating palmoplantar psoriasis.
Resistant Disease—Intralesional steroids are beneficial treatment options for recalcitrant psoriasis in glabrous areas, as well as for palmoplantar, nail, and scalp psoriasis. Up to 10 mg/mL of triamcinolone acetonide used every 3 to 4 weeks is an effective regimen.10Pregnancy/Breastfeeding—Women of childbearing potential have additional safety precautions that should be considered during medication selection. Emollients have been shown to be safe during pregnancy and lactation. Currently, there is little known about CNI use during pregnancy. During lactation, CNIs can be used by breastfeeding mothers in most areas, excluding the breasts. Evaluation of the safety of anthralin and vitamin D analogues during pregnancy and lactation have not been studied. For these agents, dermatologists need to use their clinical judgment to weigh the risks and benefits of medication, particularly in patients requiring occlusion, higher medication doses, or treatment over a large surface area. Salicylic acid should be used with caution in pregnant and breastfeeding mothers because it is a pregnancy category C drug. Lower-potency corticosteroids may be used with caution during pregnancy and breastfeeding. More potent corticosteroids and coal tar, however, should be avoided. Similarly, tazarotene use is contraindicated in pregnancy. According to the US Food and Drug Administration labels for all forms of topical tazarotene, a pregnancy test must be obtained 2 weeks prior to tazarotene treatment initiation in women of childbearing potential because of the risk for serious fetal malformations and toxicity.
Recommendations, Risks, and Benefits of Topical Therapy for the Management of Psoriasis
Topical Corticosteroids—Topical corticosteroids (TCs) are widely used for inflammatory skin conditions and are available in a variety of strengths (Table 2). They are thought to exert their action by regulating the gene transcription of proinflammatory mediators. For psoriasis, steroids are recommended for 2 to 4 weeks, depending on disease severity. Although potent and superpotent steroids are more effective than mild- to moderate-strength TCs, use of lower-potency TCs may be warranted depending on disease distribution and localization.11 For treatment of psoriasis with no involvement of the intertriginous areas, use of class 1 to 5 TCs for up to 4 weeks is recommended.
For moderate to severe psoriasis with 20% or less body surface area (BSA) affected, combination therapy consisting of mometasone and salicylic acid has been shown to be more effective than mometasone alone.12,13 There currently is a level A recommendation for the use of combination therapy with class 1 TCs and etanercept for 12 weeks in patients with moderate to severe psoriasis who require both systemic and topical therapies for disease control. Similarly, combination therapy with infliximab and high-potency TCs has a level B recommendation to enhance efficacy for the treatment of moderate to severe psoriasis.14 High-quality studies on the use of TCs with anti–IL-12/IL-23, anti–IL-23, and anti–IL-17 currently are unavailable, but the combination is not expected to be unsafe.14,15 Combination therapy of betamethasone dipropionate ointment and low-dose cyclosporine is an alternative regimen with a level B recommendation.
The most common adverse effects with use of TCs are skin thinning and atrophy, telangiectasia, and striae (Table 1). With clinical improvement of disease, it is recommended that clinicians taper TCs to prevent rebound effect. To decrease TC-related adverse effects, clinicians should use combination therapy with steroid-sparing agents for disease maintenance, transition to lower-potency corticosteroids, or use intermittent steroid therapy. Systemic effects of TC use include hypothalamic-pituitary-adrenal axis suppression, Cushing syndrome, and osteonecrosis of the femoral head.16-18 These systemic effects with TC use are rare unless treatment is for disease involving greater than 20% BSA or occlusion for more than 4 weeks.
Calcineurin Inhibitors—Calcineurin inhibitors inhibit calcineurin phosphorylation and T-cell activation, subsequently decreasing the expression of proinflammatory cytokines. Currently, they are not approved by the US Food and Drug Administration to treat psoriasis but have demonstrated efficacy in randomized control trials (RCTs) for facial and intertriginous psoriasis. In RCTs, 71% of patients using pimecrolimus cream 0.1% twice daily for 8 weeks achieved an investigator global assessment score of clear (0) or almost clear (1) compared with 21% of placebo-treated patients (N=57).19 Other trials have shown that 65% of patients receiving tacrolimus ointment 0.1% for 8 weeks achieved an investigator global assessment score of 0 or 1 compared with 31% of placebo-treated patients (N=167).20 Because of their efficacy in RCTs, CNIs commonly are used off label to treat psoriasis.
The most common adverse effects with CNI use are burning, pruritus, and flushing with alcohol ingestion (Table 1). Additionally, CNIs have a black box warning that use may increase the risk for malignancy, but this risk has not been demonstrated with topical use in humans.21Vitamin D Analogues—The class of vitamin D analogues—calcipotriol/calcipotriene and calcitriol—frequently are used to treat psoriasis. Vitamin D analogues exert their beneficial effects by inhibiting keratinocyte proliferation and enhancing keratinocyte differentiation. They also are ideal for long-term use (up to 52 weeks) in mild to moderate psoriasis and can be used in combination with class 2 and 3 TCs. There is a level A recommendation that supports the use of combination therapy with calcipotriol and TCs for the treatment of mild to moderate psoriasis.