What are the guidelines for initial treatment of psoriasis?

Initial Treatment Guidelines for Psoriasis

The initial treatment for psoriasis should begin with topical corticosteroids of moderate to high potency (classes 2 to 5) for a maximum of 4 weeks for plaques not affecting intertriginous areas. 1

Disease Classification and Assessment

• Psoriasis severity is categorized as mild (less than 3% body surface area), moderate (3-10% BSA), or severe (greater than 10% BSA), with consideration of location and impact on quality of life 2
• Assessment should include both objective measures (extent and severity of skin involvement) and the patient's perception of their disability to determine appropriate treatment strategy 1
• The diagnosis of psoriasis is primarily clinical and usually does not require complementary examinations 1

First-Line Treatment for Mild to Moderate Psoriasis

Topical Therapies

• For non-facial, non-intertriginous areas, use moderate to high potency topical corticosteroids (classes 2-5) for up to 4 weeks 1
• For facial, intertriginous, and sensitive areas, use lower potency corticosteroids to avoid skin atrophy 1
• Vitamin D analogs (calcipotriol/calcipotriene) can be used alone or in combination with corticosteroids for a synergistic effect 1
• Combined products with calcipotriol and corticosteroids are recommended for enhanced efficacy 1
• Tazarotene (topical retinoid) is effective when combined with moderate to high potency topical corticosteroids, which helps reduce irritation 1, 3
• Topical calcineurin inhibitors (tacrolimus 0.1%) are recommended for psoriasis of the face, genitalia, and body folds as they don't cause skin atrophy 1

Maintenance Strategy

• For maintenance, consider weekend-only application of corticosteroids while using vitamin D analogs on weekdays 1
• Regular clinical follow-up is essential when using topical corticosteroids 1
• Avoid prescribing renewals without medical supervision 1
• Do not exceed 100g of a moderate potency preparation per month 1
• Plan annual periods where an alternative treatment is used 1

Treatment for Moderate to Severe Psoriasis

Phototherapy

• Narrowband UVB is recommended as the first-line phototherapy option, with fewer side effects than PUVA 2
• UV therapy is particularly useful for pregnant women with moderate to severe disease and should be considered first-line in this population 4
• Phototherapy requires significant time commitment, which can impact quality of life and should be considered when deciding on treatment 4

Systemic Therapies

• For moderate to severe psoriasis (>5% BSA) or inadequate response to topical therapy, consider systemic therapies 1
• First-line systemic options include acitretin, biologic agents (infliximab, adalimumab, ustekinumab), cyclosporine, and methotrexate 4
• Cyclosporine at 3-5 mg/kg/day is particularly effective for erythrodermic psoriasis due to its rapid onset of action, but should generally be limited to a 3-4 month course 4
• Methotrexate requires careful monitoring of liver and renal function 2
• Acitretin is particularly effective for pustular psoriasis but cannot be used in women of childbearing potential due to teratogenicity 4

Combination Therapies

• Combining topical corticosteroids with vitamin D analogs provides synergistic effects and greater efficacy than either agent alone 1
• Methotrexate combined with UVB produces synergistic effects, allowing enhanced efficacy and reduced treatment duration 4
• Acitretin is effective in combination with NB-UVB or PUVA, decreasing the total number of treatments and cumulative UV exposure 4

Important Considerations and Pitfalls

• Avoid systemic corticosteroids as they can precipitate or worsen psoriasis flare-ups, especially when discontinued 1, 2
• Perceived "tachyphylaxis" to topical corticosteroids is often due to poor patient adherence rather than receptor down-regulation 1
• Treatment is suppressive, aiming to induce remission or make psoriasis tolerable, but relapses cannot be avoided with topical agents alone 1
• Some patients who do not respond to one topical agent may respond to another 1
• Medications to avoid include alcohol, beta-blockers, NSAIDs, lithium, chloroquine, and mepacrine, as they can worsen psoriasis 1
• Avoid using salicylic acid with calcipotriol, as the acidic pH will inactivate calcipotriol 1

Special Populations

• Most patients with chronic stable plaque psoriasis and guttate psoriasis can be managed by general practitioners 1
• Patients with severe psoriasis requiring systemic agents should be followed by a dermatologist due to potential toxicity 1
• For pregnant women with moderate to severe psoriasis, narrowband UVB is the first-line treatment option 4