Treatment Options for Psoriasis
Disease Severity Classification and Treatment Selection
For mild psoriasis (<5% body surface area and asymptomatic), use topical therapy as first-line treatment; for moderate-to-severe psoriasis (≥5% BSA, symptomatic disease, or significant quality of life impact), initiate phototherapy or systemic agents. 1, 2, 3
The American Academy of Dermatology emphasizes that symptomatic psoriasis (pain, bleeding, itching) warrants systemic or phototherapy regardless of body surface area involvement 1, 3. Quality of life impact should drive treatment intensity, not just physical extent 2, 3.
Topical Therapy for Mild Psoriasis
First-Line Topical Regimen
Apply calcipotriene/betamethasone dipropionate combination product once daily for 4-8 weeks, which achieves clear or almost clear status in 48-74% of patients. 1, 3
- For trunk and extremities with thick, chronic plaques, use ultrahigh-potency (class 1) corticosteroids like clobetasol propionate 0.05% or halobetasol propionate 0.05% 1, 3
- Maximum continuous high-potency corticosteroid use is 4 weeks to prevent skin atrophy, striae, telangiectasia, and HPA axis suppression 1, 3
- Maximum vitamin D analogue use is 100g per week to avoid hypercalcemia 1, 3
Site-Specific Modifications
For facial and intertriginous areas, use low-potency corticosteroids or calcitriol ointment to prevent skin atrophy. 1, 3
- Tacrolimus is first-line for intertriginous psoriasis due to efficacy without causing atrophy 1
- For scalp psoriasis, use calcipotriene foam or calcipotriene plus betamethasone dipropionate gel for 4-12 weeks 1, 3
- For nail psoriasis, apply calcipotriene combined with betamethasone dipropionate, though efficacy is limited due to poor nail matrix penetration 1
Maintenance Strategy After Initial Control
Transition to weekend-only high-potency corticosteroid application (twice daily on weekends) with weekday vitamin D analogue therapy (twice daily on weekdays) to minimize corticosteroid exposure while maintaining efficacy. 1
Phototherapy for Moderate-to-Severe Psoriasis
Narrowband UVB phototherapy is an effective first-line option for moderate-to-severe psoriasis, particularly useful for pregnant women as it lacks systemic toxicities and immunosuppressive properties. 4
- Phototherapy is typically administered 2-3 times weekly 4
- Combining methotrexate with narrowband UVB or PUVA produces synergistic effects, allowing enhanced efficacy and reduced treatment duration 4
- Acitretin combined with narrowband UVB or PUVA increases response rates and decreases cumulative UV exposure 4
- The 308-nm excimer laser allows selective targeting of localized resistant areas such as scalp and skin folds 1
Systemic Non-Biologic Therapies for Moderate-to-Severe Psoriasis
Cyclosporine for Rapid Control
For patients requiring rapid disease control, particularly those with erythrodermic psoriasis, initiate cyclosporine 3-5 mg/kg/day for short 3-4 month "interventional" courses. 4, 1, 3
- Cyclosporine provides rapid and impressive onset of action for systemically ill patients 1
- Requires monitoring of blood pressure and renal function 3
- After acute illness improves, transition to maintenance therapy 1
Methotrexate
Methotrexate is FDA-approved since 1972 and works as a competitive inhibitor of dihydrofolate reductase with anti-inflammatory effects. 1, 3
- Requires regular monitoring of complete blood count, liver function tests, and serum creatinine 3
- Subcutaneous administration bypasses the liver but may require dose titration, limiting usefulness when rapid response is needed 4
- Male patients should avoid conception until 3 months after discontinuation due to effects on spermatogenesis 4
Acitretin
Acitretin decreases keratinocyte hyperproliferation and restores normal epidermal differentiation, but cannot be used in women of childbearing potential due to teratogenicity. 4, 1, 3
- Has slower onset of action compared to cyclosporine, making it less suitable for erythrodermic psoriasis requiring rapid response 4
- Oral retinoids suppress development of cutaneous squamous cell carcinoma in patients treated with PUVA 4
Biologic Therapies for Moderate-to-Severe Psoriasis
The American Academy of Dermatology recommends biologics as an option for first-line treatment of moderate-to-severe plaque psoriasis due to their efficacy and acceptable safety profiles. 5
TNF-α Inhibitors
- Etanercept, adalimumab, certolizumab, and infliximab are approved for psoriasis 5
- Adalimumab is effective for both skin and joint symptoms in psoriatic arthritis 2, 6
- Infliximab, adalimumab, and ustekinumab are first-line biologic options 4
IL-17 Inhibitors
- Secukinumab, ixekizumab, bimekizumab, and brodalumab target IL-17 5
IL-23 Inhibitors
- Guselkumab, tildrakizumab, risankizumab, and mirikizumab target the p19 subunit of IL-23 5
IL-12/23 Inhibitor
- Ustekinumab inhibits the p40 subunit of IL-12 and IL-23 5
Combination Strategies to Enhance Efficacy
Adding ultrahigh-potency topical corticosteroids to biologic therapy accelerates clearance and improves outcomes. 1, 3
- Adding ultrahigh-potency topical corticosteroid to standard dose etanercept for 12 weeks enhances efficacy (Level I evidence) 1
- Adding calcipotriene/betamethasone to standard dose adalimumab for 16 weeks accelerates clearance 1
- Adding topical calcipotriene to standard dose methotrexate is recommended (Level I evidence) 1
- All topical corticosteroids can be used in combination with any biologics 1
- Combining tazarotene with medium- or high-potency corticosteroids for 8-16 weeks increases efficacy while reducing local adverse events 1
Special Considerations for Erythrodermic Psoriasis
For erythrodermic psoriasis, initiate oral cyclosporine 4 mg/kg/day after ruling out sepsis, as this provides rapid improvement within 2-3 weeks. 4
Initial management for all patients with erythrodermic psoriasis includes:
- Appropriate wet dressings with mid-potency topical steroids 4
- Attention to fluid balance with control of ankle edema 4
- Rule out sepsis with blood cultures 4
After achieving control with cyclosporine, taper and discontinue over 2 months while introducing maintenance therapy such as etanercept 4.
Critical Pitfalls to Avoid
Never combine salicylic acid with calcipotriene simultaneously—the acidic pH inactivates calcipotriene and eliminates its effectiveness. 1, 3
- Avoid systemic corticosteroids in psoriasis as they cause disease flare during taper 2, 3
- Do not use high-potency corticosteroids on face or flexures—use low-potency agents or tacrolimus instead 1
- Vitamin D analogues should be applied after phototherapy to avoid inactivation 2
- Avoid trimethoprim-sulfamethoxazole and other antibiotics that interact with methotrexate when patients are on MTX therapy 4
- Long-term use of high-potency corticosteroids beyond 12 weeks requires careful physician supervision 1
Oral Small Molecule Therapy
Apremilast, a phosphodiesterase 4 inhibitor, is an oral treatment option for moderate-to-severe plaque psoriasis. 5
Drugs That May Worsen Psoriasis
Avoid or use with caution: alcohol, beta-blockers, NSAIDs, lithium, chloroquine, and mepacrine, as these may precipitate or worsen psoriasis 2.