 Management
General Principles Therapy is aimed at decreasing size and thickness of plaques, reducing pruritus, alleviating arthritic symptoms, if present, and improving emotional well-being. Treatment regimens must be individualized according to age, sex, occupation, personal motivation, and other health-related conditions. Treatment selection is determined by some of the following factors: Age of patient. Oral agents that are used to treat severe psoriasis are less likely to be used in children. Very young children, particularly infants, are not able to cooperate with phototherapy treatment (described later in this chapter). Type of psoriasis. Site and extent of involvement. Health care provider's experience in managing psoriasis. Mild to moderate psoriasis can be managed by primary care clinicians and moderate to severe psoriasis is best treated by dermatologists. Availability of facilities, such as a phototherapy unit. Concurrent psychosocial problems, such as anxiety, depression, alcoholism, and substance abuse.
Available Treatment Modalities Three basic treatment modalities are available for the overall management of psoriasis: (a) topical agents, (b) phototherapy, and (c) systemic agents, including biologic therapies. Treatments may be used alone or in combination. Topical therapy is the first-line approach in the treatment of plaque psoriasis (Tables 14.1 and 14.2) and options include topical corticosteroids, coal tar, anthralin, calcipotriene, calcitriol, and tazarotene. No single agent is ideal, and many are often used concurrently in a combined approach. Auxiliary agents such as scale-removing keratolytics can also be used. Phototherapy and systemic therapy are sometimes initiated after topical treatments have been tried unsuccessfully (see also the later section titled “Generalized Plaque Psoriasis”).
Specific Treatment of Localized Plaque Psoriasis Topical Corticosteroids Disadvantages Drug tolerance (tachyphylaxis) is not uncommon. Potential side effects of topical steroids (see “Introduction: Topical Therapy”). Expensive and time consuming, especially when extensive areas are involved.
Occlusion of Topical Corticosteroids Topical Vitamin D3 Derivatives Calcipotriene (Dovonex*) and calcitriol (Vectical) are synthetic forms of vitamin D3, which slow down the rate of skin cell growth. Calcipotriene is available as a cream, ointment, and scalp solution in 0.005% strength. Calcitriol, available as Vectical ointment, is similar to calcipotriene, but is less irritating. *Dovonex in the United States, “Daivonex” outside of North America, and “Psorcutan” in Germany Taclonex is a combination product containing calcipotriene and betamethasone ointment 0.064% and is available as Taclonex ointment and Taclonex scalp solution.
Advantages Calcipotriene and calcitriol do not have side effect of thinning of the skin. May enhance the effectiveness of ultraviolet (UV) treatments. A combined maintenance treatment of daily Dovonex or Vectical plus weekend use of a superpotent topical steroid (called pulse therapy) may prolong remissions and reduce tachyphylaxis (drug tolerance). Taclonex combines a vitamin D3 analog, which reduces scale and slows skin cell growth with the anti-inflammatory effects of a steroid and is applied once daily.
Disadvantages Not as effective at decreasing inflammation and works more slowly than topical steroids. Most common minor side effects are skin irritation, stinging, or burning. Taclonex is expensive and because it contains a potent topical steroid, it should not be applied to the face, axillae, groin, or other skin folds.
Topical Tar Preparations Before the advent of topical steroids, tar preparations such as crude tar oil were the mainstay of therapy for psoriasis and most inflammatory dermatoses. Currently, they are used much less often. Coal tar can be compounded in concentrations of 0.5% to 10% into a variety of vehicles including an ointment or a shampoo. Agents such as liquor carbonis detergens, Balnetar, Doak Tar oil, Estar gel, PsoriGel, and T/Derm tar oil are the traditional tar preparations. Neutrogena T-Gel therapeutic shampoo contains 0.5% coal tar.
Topical Anthralin Anthralin is a coal tar derivative without the side effects of crude coal tar. Anthralin is used for shorter periods than coal tar, sometimes several minutes at a time; this is referred to as short-contact anthralin therapy (SCAT). Major drawbacks are the possible occurrence of skin irritation and a reversible brownish-purple staining of the skin.
Innovative Management Strategies An innovative approach consists of cycling or rotating different treatment modalities. This strategy presumably decreases cumulative side effects and drug tolerance; and it often allows for lower dosages and shorter durations of therapy for each agent. For example, a superpotent (class 1) topical steroid, such as clobetasol, may be applied for 2 weeks, discontinued for 1 or 2 weeks, and then restarted. Alternatively, clobetasol may be used on weekends only, and Dovonex cream or Vectical ointment may be used during the week.
|
Differential Diagnosis