Key Points

  • Psoriasis is a chronic inflammatory disease which can affect the skin, joints and nails
  • Psoriasis typically affects the scalp, ears, palms, soles, elbows, knees, and intergluteal cleft; it can result in erythroderma (generalized erythema) or be pustular.
  • Initial treatment of psoriasis is followed by long-term maintenance therapy.
  • Greater than 10% body surface area, or severe involvement of the scalp, hands, or feet, may require phototherapy, systemic immunosuppressive or retinoid therapies.
  • Systemic corticosteroids can lead to initial improvement of psoriasis with a rebound worsening upon steroid taper, and should be avoided.


  • Psoriasis affects around 2% of the population, although it is more prevalent among Caucasians, particularly in North America and Northern Europe.
  • Men and women are equally prone to the condition. Patients develop psoriasis between the ages of 20-30 years or later between 50-60 years.


  • The pathogenesis of psoriasis is not fully understood, and is the subject of ongoing research.
  • The current consensus is that it is a primarily T lymphocyte driven immune-mediated disorder in a genetically predisposed individual, and environmental triggering factors contribute to the manifestation of the disease.

Clinical Overview

  • Psoriasis is a chronic, intermittent skin disease classically marked by sharply-demarcated erythematous papules and plaques with silvery hyperkeratotic scale that affects the scalp, ears, palms, soles, elbows, knees, and intergluteal cleft; it usually spares the face in adults, but may involve the face in approximately half of affected children. Arthritis is associated with psoriasis in 10-30% of patients, and nail involvement is also common.
  • The disorder has a remitting and relapsing course and varies in severity from minor localized patches (mild) to complete body coverage (severe).

Plaque psoriasis: Sharply-demarcated erythematous plaques with silvery scale. Facial involvement is rare in adults but more common in children.

Guttate (rain-drop like) variant of psoriasis is sometimes following streptococcal infection (upper respiratory infection).

Erythroderma (generalized erythema) of psoriasis.

Scalp psoriasis.

Involvement of the palms/ soles is common and may be the only manifestation of psoriasis.

Nail involvement is common, associated with onycholysis, pitting, discoloration (oil spots), and onychodystrophy.

Pustular variant of psoriasis.

Psoriatic arthritis presents with typical lesions of psoriasis in association with seronegative arthritis or arthropathy.

Principles of Psoriasis Management

  • Topical therapy is usually appropriate for treatment of patients with less than 10% body surface area (see table below).
  • Systemic therapies (see table below) are indicated when one or more of the following are present:
    • Extensive body surface involvement (greater than 10% surface area)
    • Topical treatment-resistant scalp or palm/sole involvement
    • Arthritis or nail involvement
    • Generalized pustular and erythrodermic variants
Topical therapy Phototherapy Systemic therapy


Topical corticosteroids

Vitamin D3 derivatives




Topical immunomodulators








Topical therapy

Topical therapy alone offers excellent control for localized forms of psoriasis.

    1. Emollients. Liberal use of emollients to soften and hydrate the epidermis is a cornerstone of psoriasis therapy.
    2. Keratolytics. These agents remove scale, soften plaques, and enhance penetration of other therapies. They are most effective when used after adequate hydration.
      • Salicylic acid 2%-10%: Do not use on greater than 20% of the body surface area, and use caution with widespread occlusion to prevent salicylate toxicity (tinnitus, nausea, dizziness, and psychiatric disturbance).
      • Urea 20%-40% (such as Carmol, Gordon’s, Keralac, Vanamide) in petrolatum may also be used with occlusion.
    3. Topical corticosteroids.
      • Are the most commonly prescribed agents for treatment of localized psoriatic lesions.
      • High-potency topical steroids (class 1 or 2) are required, except for the face, groin, axillae, and other skin folds.
        • Clobetasol propionate 0.05% lotion, cream, ointment, foam, solution: such as Clobex, Embeline, Olux, Olux-E, Temovate
        • Betamethasone dipropionate 0.05% ointment, gel, lotion: such as Diprolene
        • Halobetasol propionate 0.05% cream or ointment: such as Ultravate
      • Occlusion will enhance local penetration, of the corticosteroid, but can cause adverse effects.
      • Combination treatment of topical steroids with vitamin D analogues (calcitriol, calcipotriene) or tazarotene may increase efficacy, decrease side effects, while sequential treatment prevents rebound and tachyphylaxis.

Corticosteroids in childhood psoriasis

Site Mild disease Moderate severity Severe disease Frequency
Face, axillae, groin Hydrocortisone 1% or 2.5% cream Hydrocortisone 2.5% cream Desonide 0.05% cream or ointment Daily to b.i.d.
Scalp Hydrocortisone 2.5% solution Triamcinolone 0.1% solution Fluocinonide 0.05% solution Daily to b.i.d.
Trunk, extremities Hydrocortisone 2.5% cream or ointment Triamcinolone 0.1% cream or ointment Fluocinonide 0.05% cream or ointment b.i.d.
Palms, soles Triamcinolone cream or ointment 0.1% Fluocinonide cream or ointment 0.05% Clobetasol lotion, spray, cream, or ointment 0.05% b.i.d.

Corticosteroids in adulthood psoriasis

Site Mild disease Moderate severity Severe disease Frequency
Face, axillae, groin Hydrocortisone 1% or 2.5% cream Desonide 0.05% cream Mometasone 0.1% cream (ointment used qday 5-7 days) Daily to b.i.d.
Scalp Triamcinolone 0.1% solution Fluocinonide 0.05% solution or Clobetasol 0.05% shampoo, solution, or foam Clobetasol 0.05% shampoo, solution, or foam Daily to b.i.d.
Trunk, extremities Triamcinolone 0.1% cream or ointment Fluocinonide 0.05% cream or ointment Clobetasol 0.05% spray, lotion, cream, or ointment b.i.d.
Palms, soles Triamcinolone 0.1% cream or ointment Fluocinonide 0.05% cream or ointment Clobetasol 0.05% lotion, cream, or ointment b.i.d.
  1. Vitamin D3 products.
    • Calcitriol 3 µg/g ointment (such as Vectical) is naturally occurring metabolite of vitamin D3, whereas Calcipotriol 0.05% cream or solution: (such as Dovonex) is a synthetic vitamin D3 analogue.
    • Used in mild-to-moderate plaque psoriasis twice daily.
    • Efficacy comparable with a mid-potency corticosteroid (betamethasone valerate 0.1%). Good safety profile. Perilesional irritation or facial/genital irritation may occur with calcipotriene while calcitriol is well tolerated on these sensitive areas.
  2. Tazarotene
    • Topical retinoid (such as Tazorac 0.05 or 0.1% gel) used as monotherapy (once daily at night, or short contact 30 minutes before shower) or in combination with topical steroids.
    • Less effective than potent topical steroids and may cause burning, erythema, scaling, and photosensitivity, pregnancy category X.
  3. Tar preparations
    • Crude coal tar:
      • 2%-10% compounded in petrolatum/nonionic base cream.
      • Can be messy to apply, has an unpleasant smell, stains skin and clothes.
      • In some countries not available because of theoretical risk of carcinogenicity.
    • Liquor carbonis detergens (LCD):
      • Refined preparation of coal tar.
      • Effective in palmar or plantar lesions.
      • After UVB light therapy (see information under Phototherapy below).
    • Tar-containing shampoos (such as Neutrogena T gel) are used in scalp psoriasis.
  4. Anthralin
    • Appropriate for both inpatient (Ingram therapy) and outpatient care.
    • Various concentrations and formulations available.
    • Short-contact therapy to minimize irritation.
    • May cause irritation, staining of skin, hair, clothes, porcelain, and furniture.
  5. Topical immunomodulators.
    • Tacrolimus ointment, pimecrolimus cream: not FDA approved in psoriasis.
    • Tacrolimus ointment (such as 0.03% Protopic ointment) b.i.d. has shown benefit in the treatment of facial, genital, and intertriginous psoriasis.

Occlusive therapy

Occlusion enhances hydration of the epidermis and promotes cutaneous penetration of topically applied drugs. Methods: Plastic gloves, shower cap, plastic wrap.

Phototherapy with UVB

  • Should be administered by specialists.
  • Broad- (290-320 nm) and narrowband (310-313 nm) UVB available for patients with widespread lesions, not responding to topicals.
  • Phototherapy requires sessions three times each week (up to five times a week) and 20-30 treatments will be required to clear lesions.

Photochemotherapy (PUVA)

  • Topical or oral administration of 8-methoxypsoralen (psoralen) and UVA (PUVA = psoralen + ultraviolet A).
  • Moderate-to-severe psoriasis requires 20-30 treatments to achieve clearing.
  • Shield the patient’s eyes, face, and male genitalia during treatment. Instruct the patient to wear protective glasses for 12 hours following psoralen ingestion.
  • Specific forms:
    1. Systemic PUVA: Oral methoxypsoralen before UVA exposure.
    2. Bath PUVA: The patient bathes for 15-30 minutes in a diluted solution of psoralen prior to UVA.
    3. Soak PUVA: Soak hands and/or feet in psoralen solution for 30 minutes prior to UVA exposure.

Pitfalls of photo- and photochemotherapy

  1. Phototherapy should not be initiated in patients with highly-inflamed or erythematous lesions, as phototoxicity may exacerbate their skin condition.
  2. It is important to counsel the patient to avoid outdoor sunlight or tanning beds during the treatment and protective prescription grade sunglasses and sunscreen should be used for several hours after ingestion of systemic psoralen.
  3. Late side effects include skin carcinogenesis (SCC > BCC > controversial increase in melanoma), enhanced photoaging, pigmentary changes (lentigines), and cataracts. To minimize these effects, shield the patient’s eyes, genitals, and face during therapy, and warn the patient to wear protective glasses and sunscreen for 12 hours following psoralen ingestion. Skin cancer screening exams are recommended.

Systemic therapy


  • Indications: Psoriatic erythroderma; acute pustular psoriasis; localized pustular psoriasis or treatment-resistant psoriasis (scalp, palms, soles, nails); psoriatic arthritis.
  • Therapy: Typical psoriasis patients respond to a dose of 15 mg per week within a period of 6-8 weeks. Recalcitrant cases may require higher doses.


  • Acitretin (such as Soriatane) is the only systemic retinoid currently approved for the treatment of psoriasis.
  • Indication: Monotherapy in the treatment of pustular and erythrodermic psoriasis, but is best used in combination with phototherapy or other systemic agents when treating moderate to severe plaque psoriasis.
  • Acitretin should not be used in females of childbearing potential or in patients with uncontrolled lipid abnormalities or active hepatitis.
  • Retinoid + UVB or PUVA can result in tolerable doses of acitretin (10-25 mg daily), faster and more complete clearing, and lower cumulative doses of UV- light.


  • Cyclosporine (such as Neoral or Sandimmune) may be used to treat a variety of severe forms of psoriasis. The clinical response is often dramatic and may result in relatively rapid control of disease, but because of potentially significant toxicity its use must be limited to one-year periods.
  • Indication: Generalized plaque psoriasis, erythrodermic psoriasis, and psoriasis of the palms and soles in immunocompetent patients who have failed other therapies. Cyclosporine is especially useful in sudden, severe flares of disease.


Hydroxyurea (such as Droxia or Hydrea) is used off-label by some in combination with other therapies, but is infrequently used as a primary agent.

Cytokine antagonists and other blockade of immune mediators

There is substantial evidence that psoriasis is primarily a T lymphocyte driven, immune-mediated disorder. The development of a new class of drugs, engineered proteins targeting specific immunologic mediators involved in psoriasis, including tumor necrosis factor alpha (TNF-A), may offer effective treatments with fewer side effects than the more broadly acting immunosuppressive agents. These agents are relatively new but have proven efficacy; data will continue to accumulate regarding long-term benefits and risks. When modulating the immune system, one is always attuned to the risk of infection, reactivation of tuberculosis, and malignancy, and these risks should be taken into consideration and discussed when screening potential patients. Baseline screening for infection (such as a PPD) and/or malignancy is recommended. Selection of an individual agent should be based on side-effect profile and access to medication, and individual agents are discussed below. Several agents are category B for pregnancy but there is emerging data that tumor necrosis blocking agents may increase risk of fetal abnormalities, and patients should be counseled accordingly.

  • Use in children: Limited data exist for the efficacy and safety of these drugs in the pediatric population. They should be administered by specialists.
  1. Etanercept (Enbrel): Recombinant, human protein that was designed to block the proinflammatory and hyperproliferative actions of tumor necrosis factor alpha (TNF-A).
    • When 50 mg twice weekly for 3 months and a 50 mg/week maintenance dose is used, 46% of psoriasis patients achieve 75% reduction in PASI score at 12 weeks, and this improvement is maintained at 24 weeks.
  2. Adalimumab (Humira): Recombinant, humanized IgG against TNF-A.
    • It is given as a subcutaneous injection weekly or every other week.
    • Approximately 75% patients may achieve 75% improvement in the PASI score at 16 weeks into the treatment versus approximately 10-20% of placebo controls.
  3. Infliximab (Remicade): Chimeric (mouse-human) IgG1 monoclonal antibody directed against TNF-A
    • Approximately 80% of patients treated achieve a 75% improvement in the PASI score by week 10, and improvement may be seen as early as 2 weeks.
  4. Ustekinumab (Stelara): Monoclonal antibody that targets the IL-12 and IL-23 cytokine pathways.
    • Dosage is 45 mg subcutaneous injection q12 weeks, often started with an injection at week 0, repeated at week 4, then q12 weeks.
    • Has shown comparable efficacy in adults to TNF-A cytokine blockade in moderate-to-severe plaque psoriasis.
  5. Alefacept (Amevive): Fully human receptor fusion protein.
    • Alefacept is relatively well tolerated, though patients must understand that response times are relatively slow. After a period of 24 weeks, approximately 33% of patients achieve 75% improvement in PASI score.

Therapy of plaque psoriasis

Plaque psoriasis is the most common form of psoriasis and may present as either localized or generalized disease. Therapeutic options are listed according to the extent of disease involvement.

Localized plaque psoriasis

  1. Initiate a regimen of topical corticosteroids and liberal use of emollients.
    • Combination or sequential therapy with vitamin D derivatives and super-potent topical steroids can yield excellent results over 2-4 weeks. Lower potency topical steroids must be used on the face, axillae, and groin.
    • Some patients may require this steroid pulse treatment as maintenance, while others may be maintained with only Vitamin D derivatives twice a day.
  2. In recalcitrant, local lesions dermatologist may prescribe intralesional or occluded corticosteroids, anthralin preparations and UV-light (excimer laser, high intensity UV lamp).

Generalized plaque psoriasis

  1. Dermatologists may select from UVB phototherapy, PUVA, Goeckerman regimen, methotrexate, acitretine, cyclosporine, biologics
  2. Combination therapies are often appropriate for patients with severe plaque psoriasis.

Therapy of scalp psoriasis

Mild Diffuse Scalp Psoriasis

  1. Shampoo for 5-20 minutes with a shampoo containing tar and/or salicylic acid on a regular or an as-needed basis. A daily shampoo may be required initially, but the process may be controlled with less frequent but regular use.
  2. If medicated shampoos are ineffective, one may add a variety of topical steroids and/or calcipotriene solution.
    • Apply a medium- or high-potency topical steroid in a vehicle that is acceptable for use on the scalp once or twice a day. The most appropriate vehicles are shampoos, foams, gels, lotions, or liquid solutions, and their use is more likely to result in a compliant patient.
    • When the scalp clears, attempt control with shampoo alone, calcipotriene solution, or the lowest-strength steroid solution that will maintain remission.

Localized thick plaques

  1. Treat with the same regimen used for mild, diffuse disease. Salicylic acid containing shampoos are often very helpful as a keratolytic to release scales from the scalp, allowing for penetration of the medication.
  2. If shampoo, topical steroids, and calcipotriene are not adequate, refer patients to the dermatologist.

Extensive severe scalp psoriasis

If therapy for localized thick plaques fails refer patient to dermatologist to consider systemic therapy.

Therapy of guttate psoriasis

This type of psoriasis may follow streptococcal upper respiratory tract infection. Throat culture or rapid antigen testing to document streptococcus and antibiotics should be considered. Therapeutic alternatives include:

  • Bland emollients, medium- or high-potency topical steroids, UVB, PUVA, short course of methotrexate or cyclosporine
  • Repeated courses of antibiotics and tonsillectomy are controversial in patients with documented relationship to streptococcus.

Therapy of erythrodermic (exfoliative) and pustular psoriasis (generalized)

Hospitalize the patient, or admit the patient to dermatology day treatment center where available.

Therapy of psoriasis of the palms and soles (localized pustular psoriasis)

  1. Apply super-potent topical steroids twice daily. Soaking palms and soles for 15-20 minutes two to three times a day in lukewarm water or a tepid tar-containing solution (e.g., coal tar emulsion; 1-2 tbsp/qt water) before steroid application can be useful. Clinical response may begin within 14-21 days.
  2. Taper therapy to the level needed to maintain control and acceptance by the patient.
  3. If satisfactory control is not achieved, systemic drugs can be used or added by the dermatologist to the above topical regimen.

Therapy of psoriasis of the nails

First-line therapy: High potency corticosteroids, tazarotene gel, vitamin D derivatives, and combinations.

  • Medications should be applied to the proximal nail and nailfold and occluded nightly with vinyl or cotton gloves.
  • Therapy may be required for at least 6 months before any benefit is appreciated, and atrophy of the nailfolds may develop with prolonged use of corticosteroids under occlusion.

Systemic agents can be introduced by dermatologist by evaluating accompanying skin and joint disease and patient disability.


  • Do not chronically treat with fluorinated steroids, even for localized lesions. If topical steroid therapy does not completely clear lesions, try a different approach or refer the patient to a dermatologist who is particularly skilled in the treatment of psoriasis.
  • Antimalarials, lithium, and beta-blockers may aggravate pustular flare and should be avoided in psoriatic patients.

Situations requiring dermatologic consultation

  • If the diagnosis is not clear
  • Joint involvement
  • Psoriasis requiring systemic immunosuppression, biologic therapy, or phototherapy
  • Localized psoriasis of the scalp, hands, feet, or nails (which often require systemic immunosuppression in the setting of severe disease)
  • Pustular, erythrodermic, generalized psoriasis

Clinical Cases

Case 1

Localized plaque psoriasis

  1. 32-year-old man with >10 year history of isolated plaques on both elbows, also with nail pitting. He is not concerned with the nail changes.
  2. Uses emollients and/or hydrocortisone daily without resolution of his symptoms.


  1. Triamcinolone 0.1% ointment b.i.d. for 1-2 weeks, followed by emollient use
  2. Follow-up evaluation at 4 weeks

Follow-up evaluation

  1. Improved; lesions resolved with only minimal persistent erythema
  2. Emollients daily
  3. Topical steroids only as needed

Case 2

Palm/foot psoriasis

  1. 52-year-old woman with long-standing psoriasis involves both palms and soles
  2. Occasional painful fissures of the skin
  3. Partial improvement with super-potent topical steroid ointments, applied twice daily, as well as tar soaks
  4. Expresses concern for use of systemic immunosuppression, but is considering it


  1. Hand/foot soak, PUVA therapy three times a week
  2. Liberal use of emollients
  3. Topical fluocinonide ointment 0.05% b.i.d. after bathing
  4. Follow-up evaluation at 12 weeks

Follow-up evaluation

Improvement noted, but only partial. The patient is now amenable to systemic immunosuppression and agrees to start low-dose methotrexate.


Carter JD, Ladhani A, Ricca LR, et al. (2009). A safety assessment of tumor necrosis factor antagonists during pregnancy: a review of the Food and Drug Administration database. J Rheumatol, 36(3):635-41.

Griffiths CE, Strober BE, van de Kerkhof P, et al. (2010). Comparison of ustekinumab and etanercept for moderate-to-severe psoriasis. NEJM, 362(2): 118-128.

Menter A, Korman NJ, Elmets CA, et al. (2009). Guidelines of care for the management of psoriasis and psoriatic arthritis: section 4. Guidelines of care for the management and treatment of psoriasis with traditional systemic agents. JAAD, 61(3): 451-485.