Psoriasis is a chronic inflammatory skin disease characterized by erythematous scaly plaques that can invoke substantial pain, pruritus, and quality-of-life disturbance in patients. Topical therapies are the most commonly used medications for treating psoriasis, with one study (N = 128,308) showing that more than 85% of patients with psoriasis were managed solely with topical medications. 1 For patients with mild to moderate psoriasis, topical agents alone may be able to control disease completely. For those with more severe disease, topical agents are used adjunctively with systemic or biologic agents to optimize disease control in localized areas.
The American Academy of Dermatology (AAD) and National Psoriasis Foundation (NPF) published guidelines in 2020 for managing psoriasis with topical agents in adults.2 This review presents the most up-to-date clinical recommendations for topical agent use in adult patients with psoriasis and elaborates on each drug’s pharmacologic and safety profile. Specifically, evidence-based treatment recommendations for topical steroids, calcineurin inhibitors (CNIs), vitamin D analogues, retinoids (tazarotene), emollients, keratolytics (salicylic acid), anthracenes (anthralin), and keratoplastics (coal tar) will be addressed (Table 1). Recommendations for combination therapy with other treatment modalities including UVB light therapy, biologics, and systemic nonbiologic agents also will be discussed.
Selecting a Topical Agent Based on Disease Localization
When treating patients with psoriasis with topical therapies, clinicians should take into consideration drug potency, as it determines how effective a treatment will be in penetrating the skin barrier. Plaque characteristics, such as distribution (localized vs widespread), anatomical localization (flexural, scalp, palms/soles/nails), size (large vs small), and thickness (thick vs thin), not only influence treatment effectiveness but also the incidence of drug-related adverse events. Furthermore, preferred topical therapies are tailored to each patient based on disease characteristics and activity. Coal tar and anthralin have been used less frequently than other topical therapies for psoriasis because of their undesirable side-effect profiles (Table 1).3
Face and Intertriginous Regions—The face and intertriginous areas are sensitive because skin tends to be thin in these regions. Emollients are recommended for disease in these locations given their safety and flexibility in use for most areas. Conversely, anthralin should be avoided on the face, intertriginous areas, and even highly visible locations because of the potential for skin staining. Low-potency corticosteroids also have utility in psoriasis distributed on the face and intertriginous regions. Additionally, application of steroids around the eyes should be cautioned because topical steroids can induce ocular complications such as glaucoma and cataracts in rare circumstances.4
Off-label use of CNIs for psoriasis on the face and intertriginous areas also is effective. Currently, there is a level B recommendation for off-label use of 0.1% tacrolimus for up to 8 weeks for inverse psoriasis or psoriasis on the face. Off-label use of pimecrolimus for 4 to 8 weeks also can be considered for inverse psoriasis. Combination therapy consisting of hydrocortisone with calcipotriol ointment is another effective regimen.5 One study also suggested that use of crisaborole for 4 to 8 weeks in intertriginous psoriasis can be effective and well tolerated.6
Scalp—The vehicle of medication administration is especially important in hair-bearing areas such as the scalp, as these areas are challenging for medication application and patient adherence. Thus, patient preferences for the vehicle must be considered. Several studies have been conducted to assess preference for various vehicles in scalp psoriasis. A foam or solution may be preferable to ointments, gels, or creams.7 Gels may be preferred over ointments.8 There is a level A recommendation supporting the use of class 1 to 7 topical steroids for a minimum of 4 weeks as initial and maintenance treatment of scalp psoriasis. The highest level of evidence (level A) also supports the use of calcipotriol foam or combination therapy of calcipotriol–betamethasone dipropionate gel for 4 to 12 weeks as treatment of mild to moderate scalp psoriasis.
Nails—Several options for topical medications have been recommended for the treatment of nail psoriasis. Currently, there is a level B recommendation for the use of tazarotene for the treatment of nail psoriasis. Another effective regimen is combination therapy with vitamin D analogues and betamethasone dipropionate.9 Topical steroid use for nail psoriasis should be limited to 12 weeks because of the risk for bone atrophy with chronic steroid use.