Psoriasis

Corticosteroids are usually used topically but may be injected into small or recalcitrant lesions. (CAUTION: Systemic corticosteroids may precipitate exacerbations or development of pustular psoriasis and should not be used to treat psoriasis.) Topical corticosteroids are used twice daily. Corticosteroids are most effective when used overnight under occlusive polyethylene coverings or incorporated into tape; a corticosteroid cream is applied without occlusion during the day. Corticosteroid potency Anti-inflammatory agents Topical dermatologic treatments are grouped according to their therapeutic functions and include Cleansing agents Moisturizing agents (emollients, skin hydrators, and softeners) Drying agents... read more is selected according to the extent of involvement.

As lesions abate, the corticosteroid should be applied less frequently or at a lower potency to minimize local atrophy, striae formation, and telangiectases. Ideally, after about 2 to 3 weeks, an emollient, vitamin D3 analog, or calcineurin inhibitor should be substituted for the corticosteroid for 1 to 2 weeks (as a rest period); this substitution limits corticosteroid dosage, reduces risk of topical corticosteroid adverse effects (eg, skin atrophy, telangiectasias, easy bruising, striae), and prevents tachyphylaxis (diminishing response to an agent after successive dosing). Topical corticosteroid use can be expensive because large quantities (about 1 oz or 30 g) are needed for each application when a large body surface area is affected. Topical corticosteroids applied for long duration to large areas of the body may cause systemic effects and exacerbate psoriasis. For small, thick, localized, or recalcitrant lesions, high-potency corticosteroids are used with an occlusive dressing or flurandrenolide tape; these dressings are left on overnight and changed in the morning. Relapse after topical corticosteroid therapy is stopped is often faster than with other agents.

Vitamin D3 analogs (eg, calcipotriol [calcipotriene], calcitriol) are topical medications that induce normal keratinocyte proliferation and differentiation; they can be used alone or in combination with topical corticosteroids. Some clinicians have patients apply calcipotriol on weekdays and corticosteroids on weekends.

Calcineurin inhibitors (eg, tacrolimus, pimecrolimus) are available in topical form and are generally well-tolerated. They are not as effective as corticosteroids but may avoid the complications of corticosteroids when treating facial and intertriginous psoriasis. It is not clear whether they increase the risk of lymphoma and skin cancer.

Tazarotene is a topical retinoid. It is less effective than corticosteroids as monotherapy but is a useful adjunct because of its keratolytic effect. It is typically used on thicker psoriasis plaques that may appear on the trunk and extremities but also may be used on the face.

Roflumilast is a topical phosphodiesterase-4 (PDE-4) inhibitor. It is particularly useful as a corticosteroid-sparing treatment for facial and intertriginous areas (eg, buttocks, groin, axillae).

Tapinarof is a topical aryl hydrocarbon receptor (AhR) agonist. It is also useful as a corticosteroid-sparing therapy on facial and intertriginous areas.

Other adjunctive topical treatments include emollients, salicylic acid, coal tar, and anthralin:

Given the availability and convenience of other agents, coal tar and anthralin are being used less frequently.

UV light therapy is typically used in patients with extensive psoriasis; however, its use is declining because of the availability of various effective systemic therapies. The mechanism of action is unknown, although UVB light reduces DNA synthesis and can induce mild systemic immunosuppression. In psoralen plus ultraviolet A (PUVA), oral methoxypsoralen, a photosensitizer, is followed by exposure to long-wave UVA light (330 to 360 nm). PUVA has an antiproliferative effect and also helps to normalize keratinocyte differentiation. Doses of light are started low and increased as tolerated. Severe burns can result if the dose of medication or UVA is too high.

Although the treatment is less messy than topical treatments and may produce remissions lasting several months, repeated treatments may increase the incidence of UV-induced skin cancer and melanoma. Less UV light is required when used with oral retinoids (the so-called re-PUVA regimen). Narrowband UVB light (311 to 312 nm), which is used without psoralens, is similar in effectiveness to PUVA. Excimer laser therapy is a type of phototherapy using a 308-nm laser directed at focal psoriatic plaques.

Methotrexate taken orally is an effective treatment for severe disabling psoriasis, especially severe psoriatic arthritis or widespread erythrodermic or pustular psoriasis unresponsive to topical agents or UV light therapy (narrowband UVB) or PUVA. Methotrexate seems to interfere with the rapid proliferation of epidermal cells. Hematologic, renal, and hepatic function should be monitored. Dosage regimens vary, so only physicians experienced in its use for psoriasis should undertake methotrexate therapy.

Cyclosporine can be used for severe psoriasis. It should be limited to courses of several months (rarely, up to 1 year) and alternated with other therapies. Its effect on the kidneys and potential long-term effects on the immune system preclude more liberal use.

Mycophenolate mofetil can be an alternative option for patients who do not respond to methotrexate or cyclosporine or those who develop toxicity from the above medications.

Systemic retinoids (eg, acitretin, isotretinoin) may be effective for severe and recalcitrant cases of psoriasis vulgaris, pustular psoriasis (in which isotretinoin may be preferred), and hyperkeratotic palmoplantar psoriasis. Because of the teratogenic potential and long-term retention of acitretin in the body, women who use it must not be pregnant and should be warned against becoming pregnant for at least 3 years after treatment ends. Pregnancy restrictions also apply to isotretinoin, but the agent is not retained in the body beyond 1 month. Long-term treatment may cause diffuse idiopathic skeletal hyperostosis Diagnosis Ankylosing spondylitis is the prototypical spondyloarthropathy and a systemic disorder characterized by inflammation of the axial skeleton, large peripheral joints, and digits; nocturnal back... read more (DISH).

Several classes of biologics (therapeutic monoclonal antibodies) have shown efficacy for the treatment of moderate to severe plaque psoriasis (1 Treatment references Psoriasis is an inflammatory disease that manifests most commonly as well-circumscribed, erythematous papules and plaques covered with silvery scales. Multiple factors contribute, including... read more , 2 Treatment references Psoriasis is an inflammatory disease that manifests most commonly as well-circumscribed, erythematous papules and plaques covered with silvery scales. Multiple factors contribute, including... read more ):

Apremilast, a PDE-4 inhibitor, is an oral small-molecule medication for plaque psoriasis; however, postmarketing data suggest it is less effective than biologics (3 Treatment references Psoriasis is an inflammatory disease that manifests most commonly as well-circumscribed, erythematous papules and plaques covered with silvery scales. Multiple factors contribute, including... read more ).

Deucravacitinib is an oral small-molecule agent that inhibits tyrosine kinase 2 (part of the Janus kinase family) and has shown efficacy for treatment of psoriasis (4 Treatment references Psoriasis is an inflammatory disease that manifests most commonly as well-circumscribed, erythematous papules and plaques covered with silvery scales. Multiple factors contribute, including... read more , 5 Treatment references Psoriasis is an inflammatory disease that manifests most commonly as well-circumscribed, erythematous papules and plaques covered with silvery scales. Multiple factors contribute, including... read more ). Tofacitinib, a Janus kinase inhibitor that is sometimes used to treat psoriatic arthritis, also appears to be effective for skin-limited psoriasis (6 Treatment references Psoriasis is an inflammatory disease that manifests most commonly as well-circumscribed, erythematous papules and plaques covered with silvery scales. Multiple factors contribute, including... read more ); however, more studies are needed before it is routinely used for this indication.

Spesolimab is an IL-36 inhibitor that may be used to treat generalized pustular psoriasis.

Biosimilar medications are being developed and used for various therapeutic monoclonal antibodies as their patents expire (7 Treatment references Psoriasis is an inflammatory disease that manifests most commonly as well-circumscribed, erythematous papules and plaques covered with silvery scales. Multiple factors contribute, including... read more ). These medications have very similar efficacies and toxicities to reference products; slight differences in components are not clinically meaningful.

Other immunosuppressants (eg, hydroxyurea, 6-thioguanine) have narrow safety margins and are reserved for severe, recalcitrant psoriasis. Efalizumab is no longer available in the United States or Canada because of increased risk of progressive multifocal leukoencephalopathy Progressive Multifocal Leukoencephalopathy (PML) Progressive multifocal leukoencephalopathy (PML) is caused by reactivation of the JC virus. The disease usually occurs in patients with impaired cell-mediated immunity, particularly patients... read more .

Choice of specific agents and combinations requires close cooperation with the patient, always keeping in mind the untoward effects of the treatments. There is no single ideal combination or sequence of agents, but treatment should be kept as simple as possible. Monotherapy is preferred, but combination therapy is the norm. First-line treatment for psoriasis includes topical corticosteroids and topical vitamin D3 analogs (either as monotherapy or in combination).

Rotational therapy refers to the substitution of one therapy for another after 1 to 2 years to reduce the adverse effects caused by chronic use and to circumvent disease resistance. Sequential therapy refers to initial use of potent agents (eg, cyclosporine) to quickly gain control followed by use of agents with a better safety profile. Immunosuppressants achieve clearance or near clearance of lesions more often than methotrexate or narrowband UVB.

Mild plaque psoriasis can be treated with emollients, keratolytics, tar, topical corticosteroids, corticosteroid-sparing topical agents (eg, calcineurin inhibitors, PDE-4 inhibitors, tapinarof), vitamin D3 analogs, or anthralin alone or in combination. Moderate exposure to sunlight is beneficial, but sunburn can induce exacerbations.

Moderate to severe plaque psoriasis should be treated with topical agents and either phototherapy or systemic agents. Immunosuppressants are used for moderate to severe disease unresponsive to other agents.

Scalp plaques are notoriously difficult to treat because they resist systemic therapy, and because hair blocks application of topical agents and scale removal and shields skin from UV light. A suspension of 10% salicylic acid in mineral oil may be rubbed into the scalp at bedtime manually or with a toothbrush, covered with a shower cap (to enhance penetration and avoid messiness), and washed out the next morning with a tar (or other) shampoo. More cosmetically acceptable corticosteroid solutions can be applied to the scalp during the day. These treatments are continued until the desired clinical response is achieved.

Resistant skin or scalp patches may respond to local superficial intralesional injection of triamcinolone acetonide suspension diluted with saline to 2.5 or 5 mg/mL, depending on the size and severity of the lesion. Injections may cause local skin atrophy, which is usually reversible.

Severe cases of scalp psoriasis may need to be treated with systemic immunosuppressants (eg, biologics, small molecules).

Special treatment needs for subtypes of psoriasis Subtypes of Psoriasis are described above.

For psoriatic arthritis Psoriatic Arthritis Psoriatic arthritis is a seronegative spondyloarthropathy and chronic inflammatory arthritis that occurs in people with psoriasis of the skin or nails. The arthritis is often asymmetric, and... read more , treatment with systemic therapy is important to prevent joint destruction; methotrexate or other immunosuppressants (eg, TNF inhibitors) may be effective.

(See also the American Academy of Dermatology's clinical guideline for psoriasis.)