Psoriasis is a complex disorder that negatively impacts quality of life. Treatment strategies must address both psychosocial and
physical aspects of the disease. Psoriasis can be categorized into localized and generalized forms for treatment purposes. In either
case, the treatment plan should include obtaining rapid control of the disease and maintaining that control. For localized disease,
recent data support the combined use of topical corticosteroids with a noncorticosteroid agent (topical calcipotriene or tazarotene).
For generalized disease, UVB phototherapy is an effective treatment that permits both rapid control and long-term maintenance. Use
of low doses of acitretin (25mg qd or qod) potentiates both UVB and PUVA therapy. For patients unresponsive to phototherapy or
who are not able to come on a regular basis, methotrexate is an effective alternative. Cyclosporine is useful, especially for short-term
use in settings of acute exacerbation, but should be replaced by other modalities for long-term maintenance. Other agents that have
a place in treatment of generalized psoriasis include hydroxyurea and mycophenolate mofetil.
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Introduction
Psoriasis is a complex disorder,a multigenic phenomenon in which certain infectious, pharmaceutical, and recreational
(alcohol,cigarettes) agents may play an important role as triggers. In addition, patients commonly point out the role of stress in
psoriatic flares. Dry skin appears to act similarly to other skin injuries in initiating Koebnerization. When initiating psoriasis therapy,
psychosocial factors such as stress and alcohol use should be addressed as well as the other precipitating factors.
Quality of life in psoriasis
There is growing emphasis on quality of life research in all of medicine, and psoriasis impacts on every dimension of health-related
quality of life. In my patient population, many of my patients are spending an hour a day taking care of their psoriasis and are using
numerous treatments (including alternative medicines). Psoriasis treatment is costly, financially and psycologically. Twenty-five
percent of our patient population with psoriasis reported that in some time during their life they wished they were dead because of
their psoriasis. Eighty percent of patients with psoriasis report that stress makes their psoriasis worse and most feel that their
psoriasis itself is a very significant stressor. Specific aspects of the disease that are particularly bothersome to patients include
itching, appearance, scaling, and their inability to control the psoriasis.] An effective dermatologist must address the specific aspects
of the disease that concern each individual patient.
When one compares the quality of life in psoriasis to that in other medical conditions it becomes clear that the reduction in quality of
life that these patients experience is comparable to the reduction in quality of life with other medical illnesses. On the physical
dimensions of health-related quality of life, psoriasis has less impact than congestive heart failure, but greater impact than
hypertension, diabetes, post-myocardial infarction and depression. However, on the mental dimensions of health-related quality of
life, psoriasis was considered worse than all these conditions except depression. These findings have importance not just for
psoriasis but for skin disease in general. These are not cosmetic problems; these diseases cause quantifiable reductions in
health-related quality of life. The National Psoriasis Foundation (NPF) was founded with the goals of providing psychosocial support
and education to psoriasis patients. It is important for dermatologists to encourage their patients to join this supportive and politically
effective organization.
Treatment goals
It is helpful to set with patients a realistic goal of therapy. Generally, a goal of complete clearance of psoriasis is not realistic; few
patients actually achieve prolonged clearance. To minimize adverse medication effects, it is safest to try to reduce the psoriasis to a
manageable level, rather than to maximize doses in an attempt to obtain complete clearing. The histopathology of psoriatic lesions
reveals inflammation, keratinocyte hyperproliferation, and vascular dilation, offering multiple targets for intervention. Often, a
combination of modalities can be utilized to enhance the therapeutic effect and minimize the adverse effects that could result from
excessive use of one agent.
Treatment of localized psoriasis
Treatments for Localized Psoriasis
Tar
Topical corticosteroids
Topical calcipotriene
Topical tazarotene
Anthralin (short contact therapy)
Corticosteroid tape (Cordran tape)
Intralesional triamcinolone
For treatment purposes, we can define localized psoriasis as present when the patient is willing to apply topical therapy to all the
spots (usually less that 20% body surface area). Thus, the primary treatment options for localized psoriasis include tar preparations,
topical corticosteroids, topical calcipotriene (Dovonex), topical tazarotene (Tazorac) and anthralin Other useful treatments include
occlusive corticosteroid tape for chronically excoriated lesions of psoriasis, and intralesional triamcinolone injections for very localized,
refractory lesions.
Tar
Tar has limited effectiveness and may be used at night with more appealing topical corticosteroid preparations during the day. There
are continued "advances" in tar treatments reported but little if any scientific evidence to show that these new tar treatments are more
effective than any other. For example, patients may have heard about Exorex, a tar with banana peel extract. One marketing study
suggested that it could be as effective as topical calcipotriene, however, the patient number was so small that no valid conclusions
can be drawn.
Topical corticosteroids
Topical corticosteroids are a mainstay in the treatment of localized psoriasis and are used in their appropriate potency in their
appropriate settings. "Skin Cap," a seemingly miraculous OTC product thought to contain only a formulation of zinc pyrithrone, was
removed from the market when it was revealed that it contained clobetasol propionate. In an effort to duplicate the popular product,
the company which markets "DermaZinc" readily supplies information on compounding its product with clobetasol. Direct comparisons
of efficacy of this compounded product with commercially available clobetasol products are not available. However, studies of topical
clobetasol solution (Temovate scalp) showed that 80% of patients in the clinical trials had 80-100% improvement in only two weeks.
Increased efficacy by compounding with DermaZinc will be difficult to show.
Topical Corticosteroids
Efficacy is dependent on compliance
Consider oil or foam vehicles for scalp involvement
May be mixed with salicylic acid for treatment of hyperkeratotic lesions
Use when there is underlying dermatitis causing the Koebner phenomenon or for superimposed lichen simplex chronicus
Another advance in the area of topical corticosteroids for psoriasis is the development of betamethasone valerate in a new foam
vehicle delivery system (Luxiq). It is designed and approved for scalp treatment, though patient preference for this vehicle is very high
and there is no reason not to use it on non-scalp sites. The foam melts only when it reaches body temperature, therefore, steroid
delivery will be to the scalp and not the hair. Gram per gram it is priced the same as brand name mid potency topical steroids but it
comes in a 100 g can. Also, it appears that it covers about the same area of skin as do other topical corticosteroids when considered
on a gram per gram basis. It is very easy to apply.
Topical calcipotriene (Dovonex)
Topical calcipotriene became available in the U.S in 1994. In the original studies designed to demonstrate efficacy, the drug was used
as monotherapy with twice daily dosing, and demonstrated similar efficacy to fluocinonide ointment. However, the effects of the drug
occur more slowly than seen with Class I or II topical corticosteroids and require 8 to 12 weeks for maximal effect. In addition, the side
effect of irritation occurs in 10-15% of patients. In clinical practice, many patients will not continue to apply a medication for the 8-12
weeks necessary to see the full benefit of treatment and will also immediately discontinue use of a drug if they experience irritation
from the product. Using topical calcipotriene in combination with topical corticosteroids facilitates more rapid improvement in the
psoriasis and prevents the side effect of irritation.The combination that has been best characterized is with halobetasol (Ultravate).
Concomittant use of halobetasol cream or ointment or halcinonide (Halog) with calcipotriene scalp solution does not appear to
inactivate calcipotriene, though some other corticosteroid preparations may. In additon, calcipotriene should not be combined with
salicylic acid or other acid products, as calcipotriene is rapidly inactivated in an acidic environment. [19] A safe, effective approach to
treatment of localized psoriasis is to apply both topical calcipotriene and topical halobetasol twice daily. Rapid improvement may be
expected in 2 weeks, faster than when either agent is used alone. Once significant improvement is attained, it may be best to taper off
the potent topical corticosteroid quickly. A sensible approach may be first to switch to weekend use of the topical corticosteroid while
continuing the twice daily topical calcipotriene and then stopping the topical corticosteroid altogether.
Topical Calcipotriene
Best used in combination with potent topical corticosteroids
One of the safest treatments for psoriasis (consider use in children or in patients with HIV infection)
No monitoring required with doses <120 g/wk (scale doses down in children based on body surface area)
Do not combine with salicylic acid or other acid agents
Effective in combination with UVB and PUVA
Hypercalcemia has been reported with topical calcipotriene, but it is rare as long as the dose is maintained under 120 g/wk in adults.
At such doses, no monitoring is required unless there are preexisting conditions predisposing to hypercalcemia. Topical calcipotriene
should not be combined with salicylic acid or other acid products, as topical calcipotriene is rapidly inactivated in an acid
environment.[19] Topical calcipotriene scalp solution may be used in combination with halcinonide (Halog) solution and perhaps other
topical steroids solutions, but it should not be mixed with 6% salicylic acid (as has been done with the combination of 6% salicylic acid
[Keralyte gel], fluocinonide [Lidex] gel, and tar [Estar] gel for the treatment of hyperkeratotic lesions of psoriasis.
Another issue with topical calcipotriene is its use in combination with ultraviolet light (UVL) treatment. The combination of topical
calcipotriene with either UVB or PUVA is synergistic. There are data that topical calcipotriene is inactivated by UVA, so it is best not to
apply it immediately before PUVA treatment.] Moreover, topical calcipotriene can absorb UVB, so it is best not to apply a thick layer
immediately before going out in the sun or before getting into a UVB lightbox.
Topical calcipotriene is very safe. Though hypercalcemia has been reported, it is extremely rare if the dose is kept under 120 g/wk.
The package insert for topical calcipotriene recommends it not be used on the face or intertriginous areas due to irritation. However, if
used in combination with a topical corticosteroid initially, irritation is unlikely. Topical calcipotriene may be the safest treatment for
long-term control of face or genital disease because there is no risk of atrophy.
Topical tazarotene Table 4: Topical Tazarotene (0.1% and 0.05%)
Cosmetically pleasing gel formulation, once daily dosing
Limited efficacy and high potential for irritation when used as a monotherapy
More effective with less irritation when used in combination with topical corticosteroids
May be used in combination with phototherapy]
Retinoids are potentially teratogenic
Another drug used similarly to topical calcipotriene is topical tazarotene gel (Tazorac 0.05 and 0.1%).] An advantage of this product is
that it is applied once per day and is a gel that is more cosmetically pleasing than the ointment vehicles typically used to treat
psoriasis. It can be used on the face or scalp (the 0.1% gel is FDA-approved as a treatment for treatment for acne). Tazorac works
less quickly than high potency topical corticosteroids, with approximately 70% response at 3 months.Typical retinoid side effects of
burning and itching occur in 20-40% of patients in clinical trials and approximately 10% drop out. Patients must be told of the potential
for irritation, and tazarotene should probably only be used in combination with Class I or II topical corticosteroids both to improve
efficacy and to help minimize the potential for irritation.
Tacrolimus (Prograf)
Tacrolimus is a specific modulator of T-cell function approved for the treatment of renal allograft rejection. Topical tacrolimus
(formulated to 0.03-0.3%) has been the subject of considerable recent enthusiasm. While effective for atopic dermatitis, it is less
effective for psoriasis. This may be due to poor penetration through psoriatic plaque. It is not yet known whether its penetration and
efficacy in psoriasis would be aided by concomitant use of salicylic acid or other keratolytics.
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