An in-depth report on the causes, diagnosis, treatment, and prevention of psoriasis.
Topical medications are those applied only to the surface of the body. They come in the following forms:
In general, topical treatments are the first line for mild-to-moderate psoriasis, but they may also be used, alone or in combination, with more powerful treatments for moderate-to-severe cases.
Benefits. Corticosteroid topical treatments are the mainstays of psoriasis treatments in the US, and are effective for most patients. They have many benefits, including the following:
Brands differ in potency (strength), and many are available in numerous forms, including lotions, solutions, creams, emollient creams, ointments, gels, sprays, and on tape. Foam preparations are in particular making compliance (following treatment recommendations) much easier. Injections of certain steroids, such as triamcinolone, may help treat nail psoriasis.
Corticosteroids are available in a wide range of potencies, generally given as follows:
Topical Treatment. An example of a topical treatment that uses a single agent is as follows:
In the past, topical steroids have been used twice a day. Studies are reporting, however, that certain agents can be used effectively only once daily. Most studies have used high-potency steroids, but a 2001 study suggested that medium-potency agents, such as triamcinolone (Aureocort, Tri-Adcortyl), may be equally beneficial as a once-daily treatment. In any case, however, corticosteroids used alone are effective in clearing psoriasis in only 4 - 36% of patients.
Combinations with other drugs are often needed. For example, an effective, topical regimen uses the following combination for maintenance therapy:
In one study, over three-quarters of patients with mild-to-moderate psoriasis remained in remission for at least 6 months with this regimen.
Side Effects. The more powerful a drug, the more effective it is. But it also has a higher risk for severe side effects. They can include the following:
Do not use corticosteroids during pregnancy or nursing. The high-potency drugs carry a small risk for adrenal insufficiency , which is usually mild. If this occurs, the body loses its ability to produce natural steroid hormones for a period of time after the drug has been withdrawn, which can cause serious complications. With topical steroids, however, this event is uncommon and usually mild.
Loss of Effectiveness. In most cases, the patients become tolerant to the effects of the drugs, and the drugs become ineffective. Some experts recommend using intermittent therapy (also called weekend or pulse therapy). This type of treatment involves applying a high-potency topical agent for 3 full days each week. In one study, intermittent treatment maintained improvement for 6 months in 60% of patients.
Some Topical Corticosteroids Used for Psoriasis |
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Low potency (some are available over the counter) |
Hydrocortisone low potency (Hytone, Penecort, Synacort, Cort-Dome, Nutracort, Westcort) Desonide (Tridesilon, DesOwen) Flumethasone pivalate (Locorten) Fluocinolone acetonide (Synalar, Derma-Smoothe) Triamcinolone acetonide (Aristocort) |
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Low to medium potency |
Alclometasone dipropionate (Aclovate) Hydrocortisone low to medium potency (Locoid, Pandel) Hydrocortisone valerate (Westcort) Prednicarbate (Dermatop) |
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Medium to upper-mid potency |
Clocortolone pivalate (Cloderm) Fluticasone propionate (Cutivate). A low-dose ointment (0.005%) is proving to be effective for psoriasis on the face and in folds of the skin, but not in other areas. Mometasone furoate (Elocon). This drug is used only once a day. May be as or more effective than other corticosteroids at the same strength, while having a lower risk for severe side effects. Triamcinolone acetonide (Aureocort, Tri-Adcortyl, Kenalog). Available as a topical cream or as an injectable agent to treat nail psoriasis. |
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High potency |
Betamethasone (Diprosone) -- also available in lower potencies. Amcinonide (Cyclocort) Desoximetasone (Topicort) Diflorason diacetate (Florone, Maxiflor) Fluocinonide (Lidex) Halcinonide (Halog) |
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Very high potency |
Halobetasol propionate (Ultravate) Betamethasone (Diprolene) -- available as a foam (Luxiq). Clobetasol propionate (Temovate) -- also available as a foam (Olux). Diflorasone diacetate (Florone, Maxiflor, Psorcon). Psorcon is a gel form that may be particularly helpful. |
Coal tar preparations have been used for psoriasis for about 100 years, although their use has declined with the introduction of topical vitamin D3-related medicines. Crude coal tar stops the action of enzymes that contribute to psoriasis, and helps prevent new cell production. Tar is often used in combination with other drugs and with ultraviolet B (UVB) phototherapy.
Side Effects. Preparations have the following drawbacks:
Benefits. Anthralin (Dritho-Scalp, Drithocreme, Micanol), called dithranol in Europe, is related to a traditional medication called chrysarobin, in use since the early 1900s. Anthralin slows skin cell reproduction and can produce remissions that last for months. It is recommended only for chronic or inactive psoriasis, not for acute or inflamed eruptions.
Side Effects. As with tar, its use has also declined with introduction of the topical vitamin D-related medicines, but newer formulations, such as Micanol, have made its use more tolerable. Micanol (Psoriatec) is an anthralin formulated in micro-capsules, which dissolve and allow the drug to be delivered directly to the target skin areas. It is particularly useful for scalp psoriasis, and it is less likely to stain, unlike anthralin.
Application. Apply anthralin only to the psoriasis plaques. Many people use disposable gloves to avoid staining hands. The areas can usually be protected with dressings. Rub the cream in well, and wipe off any excess. Wash off only with lukewarm water, not soap. Using hot water will trigger the staining action. A technique called short-contact anthralin therapy (SCAT), also called minute therapy, is useful for local areas of psoriasis. In such cases, anthralin is applied for only 10 minutes to an hour.
A topical (rub-on) form of vitamin D3, calcipotriene (Dovonex), called calcipotriol in Europe, is proving to be both safe and effective. It is now available in a foam preparation, which makes compliance even easier. Several other topical vitamin D3 analogs (related drugs) showing promise include maxacalcitol (Oxarol), tacalcitol, and calcitriol (Silkis), the active form of vitamin D.
Benefits. Calcipotriene has the following benefits:
It is at least as effective as moderate topical corticosteroids, short contact anthralin, and coal tar in improving mild to moderate plaque psoriasis. Unlike steroids, patients do not develop thinning of the skin or tolerance to the drug.
Combinations. Combinations with other topical and oral treatments may improve effectiveness.
Side Effects of calcipotriene include the following:
Retinoids are related to vitamin A. They are used for various skin disorders. Tazarotene (Tazorac) is the first topical retinoid found to be effective for mild-to-moderate psoriasis. It is available in cream or gel from.
Benefits. Tazarotene benefits the targeted skin tissue without causing the bad body-wide effects of oral retinoids. Also unlike steroids, patients do not develop thinning of the skin or tolerance to the drug. Only a very small amount is needed on each lesion. It can be used on the scalp and nails, but it is not recommended for the genital areas or around the eyes. The gel should be used on only 20% of the body at anytime, the cream on up to 35%. As mentioned above, the palm of the hand is about 1% of the body surface.
Side Effects. Tazarotene can cause dryness and irritation on normal skin. Applying zinc oxide around the treated area can protect the healthy skin. Using a moisturizer can help reduce dryness. At levels high enough to be effective for psoriasis, tazarotene can cause severe skin irritation. This medicine, then, is usually used in combination with other treatments, therefore allowing a lower dose. Mixing the drug in equal amounts with petroleum jelly (Vaseline) initially and then gradually increasing the amount of tazarotene may help the skin areas become less sensitive. It should be noted that the skin can become very red while it is actually improving.
Vitamin A derivatives (drugs related to vitamin A) have been associated with birth defects, and the drug should not be used by women who are pregnant, who wish to conceive, or who are nursing.
Combinations. Combinations, such as with topical steroids or phototherapy, are more effective than the use of the drug alone. Unlike vitamin D3, phototherapy with either UVA or UVB inactivates this medicine, although there is a higher risk for sunburn with this combination.
Topical salicylic acid is useful for removing scaly plaque and enhancing other agents. It should not be used to cover wide areas of the body, since it can cause nausea and ringing in the ears. Combinations with high potency steroids, such as mometasone furoate (Combisor), clobetasol propionate, and betamethasone, are proving to be very helpful. Only Combisor is available in the US.
Occlusive TapesWatertight (occlusive) tapes or wrappings may help heal psoriasis. Occlusive tapes are particularly useful for psoriatic cuts on the palms and soles. (In such cases, the tape should be applied across the cuts until they heal.) Occlusive tapes retain sweat, which helps restore moisture to the outer skin layer and prevent scaling. They also protect against abrasion and irritation. High-Potency Corticosteroid Tapes. Applying a corticosteroid beneath an occlusive tape, or using a tape that already has a potent corticosteroid (Cordran Tape), such as flurandrenolide, may be especially beneficial. Studies are showing that high-potency corticosteroid-impregnated tapes (tapes that have corticosteroids in them) are more effective than using high-potency corticosteroid ointments alone. The downsides are:
The use of corticosteroids under occlusive materials on large areas of psoriasis increases the risk for adrenal insufficiency, a sometimes dangerous condition that occurs because the body loses its ability to produce natural steroids. Children are especially vulnerable to this effect. Other Medications with Occlusive Tapes or Wrappings. One study applied a cream containing fluorouracil underneath an occlusive tape. Fluorouracil is a powerful medication that interferes with cell growth. The dressing was applied two or three times a week for an average of about 16 weeks and resulted in 90% clearing in 11 out of 15 patients. Improvement lasted beyond 3 months in five patients. Dovonex is also sometimes used with an occlusive wrapping. Occlusive wrappings are not usually used with tazarotene (Tazorac) and should never be used without a doctor's recommendation. |
Numerous topical agents are under investigation. One such agent, tacrolimus (Protopic), is an immunosuppressant that is proving to be useful in allergic skin disorders and is being studied for psoriasis. Studies have been mixed on its benefits, although new delivery methods may make it more effective. It may prove to be safe for sensitive areas, such as the face. Pimecrolimus (Elidel), a similar agent, is also being studied.
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