Psoriasis is an itchy, uncomfortable, hyperproliferative dermatologic condition that tends to affect patients’ elbows, knees, scalp, umbilicus, lumbar regions, fingernails, toenails, and areas with skinfolds.
Psoriasis is an itchy, uncomfortable, hyperproliferative dermatologic condition that tends to affect patients’ elbows, knees, scalp, umbilicus, lumbar regions, fingernails, toenails, and areas with skinfolds. Although psoriasis is common—5.5 million Americans have it1—for 80% of them, it is mild, affecting less than 3% of the skin’s surface.2 For the remaining 20% who have moderate to severe psoriasis (affecting 3% to 10% of sufferers, respectively), this condition can affect 10% of the skin and be socially and financially crippling.3 Psoriatic arthritis is the most severe form.3,4 Psoriasis has many unique presentations (Table 14,5).
In normal individuals, skin cells turn over in 28 days; with psoriasis, the process accelerates to every 3 days when the immune system “misfires.”4 Individuals with a psoriasis diagnosis have increased production of dendritic antigen-presenting cells. That causes naïve T cells in the skin to differentiate into T helper-1 and T helper-17 cells. The body responds with an immune response characterized by cytokine release that elevates tumor necrosis factor (TNF) alpha, interleukin (IL)-12, IL-23, IL-17, and interferon gamma. Cytokine upregulation causes skin inflammation and hyperproliferation. Cells, forced to the skin surface, accumulate as dead, silvery/white scales (psoriatic plaque).5
Psoriasis is generally regarded as a young person’s disease because its median age at onset is 25 years in women and 28 years in men.5 The onset is bimodal, with another peak at around age 50. Some patients have a genetic predisposition. Although the condition is chronic and immune-mediated, its symptoms generally improve in the summer and worsen in the winter.6 Over time, patients usually identify environmental triggers that exacerbate their symptoms.2 Betablockers, lithium, antimalarials, and nonsteroidal anti-inflammatory drugs may induce or exacerbate psoriasis.7
Undertreatment is a serious concern.8 The National Psoriasis Foundation recently reported data from 5600 randomly sampled patients with psoriatic diseases. The results (Online Table 2) support the proposition that many patients could benefit from better treatment. In addition, roughly half of patients with psoriasis or psoriatic arthritis were dissatisfied with their medical care.8
Table 2: Proportion of Patients with Psoriasis Who Are Undertreated
TOPICAL TREATMENT ONLY
Most clinicians use the American Academy of Dermatology’s 6-part guidelines to structure care based on the severity of a patient’s psoriasis.2,4,9-12 The bottom line: every patient’s care must be individualized. Part 6 of the guidelines includes numerous algorithms for treatment of various kinds of psoriasis, although it does not yet include the newest agents.4
Topical therapies are the mainstay for mild disease, either as monotherapy or in combination.10 Topicals are also used in conjunction with phototherapy, traditional systemic agents, or biologic agents for moderate to severe disease.10 Drugs delivered topically can be intensified by using occlusive vehicles (eg, ointments rather than creams or lotions) and dressings. Occlusive methods significantly increase corticosteroid potency, so they should be used sparingly.2,10
Phototherapy, photochemotherapy, and traditional systemic agents are generally used forindividuals with moderate or severe disease and in situations in which topical therapy is ineffective or otherwise contraindicated. Phototherapy and photochemotherapy are effective, economical, and nontoxic, but can be costly and inconvenient.12
In general, traditional systemic agents (methotrexate [MTX], acitretin, cyclosporine, and others) have well-known short- and longterm toxicity profiles. Traditional systemic agents are given orally (MTX may also be given by injection) and are less expensive than injectable biologic agents.11
Thanks to biologics and the newest agents, clear or almost clear skin is a realistic treatment goal for almost all patients.9,13 Safety data for the new agents are reassuring.9 These new agents include the following:
• Anti-IL-17A agents: ixekizumab and secukinumab
• TNF-alpha blockers: adalimumab, adalimumab-atto, etanercept), etanercept-szzs, and infliximab
• An IL-12 and IL-23 blocker: ustekinumab
The adverse effects (AEs) of biologics can include injection-site swelling or rash and increased risk of infections, including tuberculosis, lymphoma, and nonmelanoma skin cancer.9 Apremilast, an oral phosphodiesterase-4 inhibitor, is used for treating psoriasis and psoriatic arthritis. Its most common AEs are diarrhea, nausea, and headache. In addition, patients who have psoriasis may employ other interventions. Online Table 314,15 lists some of the most common and effective alternative treatments.
Table 3: Alternative Interventions for Psoriasis
Patients May Ask About
Know the Facts
Dead Sea Salts (balneotherapy)
Dead Sea salts and other concentrated salt rock added to bath water can soften psoriasis scale and soothe itching. Used with phototherapy, sea salts improve skin symptoms more than ultraviolet B monotherapy.
Cooking oil or shortening as moisturizers for psoriatic lesions
Greasy products work best for locking moisture into psoriatic skin.
Cooking oil and shortening can be cost-effective substitutes for OTC moisturizers.
Wrapping skin in cellophane
This method involves covering topical therapies and moisturizers with plastic wrap, cellophane, waterproof dressing, or cotton or nylon socks to increase their effectiveness. Use only if recommended by the prescriber because occlusion increases potency significantly.
Topical steroids and stretch marks
Common adverse effects include stretch marks, skin thinning, pigmentation changes, easy bruising, redness, dilated surface blood vessels, and acne.
Because most patients use more than 1 topical, pharmacists should counsel them about the order of application. This can be confusing for patients and health care providers, and available guidance is inconsistent. Most dermatologists suggest the following16,17:
Patients who use medicated products should use the cleanser first and apply medicated products before cosmetics. Products with the thinnest consistency should be applied before thicker, creamy, or ointment-based products because occlusive products may prevent other products from penetrating the dermis. Each topical should be allowed to dry before the next one is applied. Note one exception: well-moisturized skin may need less corticosteroid, so if the skin is very dry, patients should moisturize before applying the corticosteroid product.16,17
Most patients with psoriasis require multiple treatment approaches the remainder of their lives. However, psoriasis waxes and wanes. Sometimes, patients report that a medication is working, but improvement may be short lived. Patients must be prepared to try medications for adequate durations, as stubborn symptoms can take weeks to months to resolve.
Ms. Wick is a visiting professor at the University of Connecticut School of Pharmacy.