What is the treatment for psoriasis?

Treatment for Psoriasis

For mild psoriasis (<5% body surface area), initiate treatment with high-potency topical corticosteroids combined with calcipotriene (vitamin D analog), which achieves 58-92% clearance rates. 1

Disease Severity Classification and Treatment Selection

Treatment selection depends on body surface area involvement and symptom severity:

• Mild psoriasis is defined as <5% body surface area (BSA), typically asymptomatic with minimal quality of life impact 2, 3
• Moderate-to-severe psoriasis is ≥5% BSA OR involvement of vulnerable areas (face, genitals, hands, feet) OR symptomatic disease (pain, bleeding, itching) OR significant quality of life impact 2, 3
• Patients with symptomatic psoriasis should be considered for systemic or phototherapy even if BSA involvement is limited 2

First-Line Treatment: Mild Psoriasis (<5% BSA)

Start with combination topical therapy:

• Apply calcipotriene/betamethasone dipropionate combination product once daily for 4-8 weeks, which achieves clear or almost clear status in 48-74% of patients 3
• Alternatively, use clobetasol propionate 0.05% or betamethasone dipropionate 0.05% twice daily for a maximum of 2-4 weeks for body plaques 1
• Combining calcipotriene with corticosteroids enhances efficacy and reduces irritation compared to monotherapy 1, 2

Important topical corticosteroid safety guidelines:

• No more than 100 g of a moderately potent preparation should be applied each month 4
• Regular clinical review is required with no unsupervised repeat prescriptions 4
• There should be periods each year when alternative treatment is employed 4
• Long-term use can cause skin atrophy, striae, and telangiectasia 2

Alternative topical agents if first-line fails:

• Coal tar (0.5-1.0% crude coal tar in petroleum jelly, increasing to maximum 10%) is extremely safe and effective 4
• Dithranol (anthralin) starting at 0.1-0.25% concentration, increased in doubling concentrations as tolerated, can be used in "short contact mode" (15-45 minutes every 24 hours) 4

Special site considerations:

• For scalp psoriasis, use calcipotriene foam or calcipotriene plus betamethasone dipropionate gel for 4-12 weeks 2, 3
• For facial and intertriginous psoriasis, use low-potency corticosteroids to avoid skin atrophy 2

Second-Line Treatment: Moderate-to-Severe Psoriasis (≥5% BSA)

Phototherapy is first-line for moderate-to-severe disease:

• Narrowband UVB or PUVA are recommended as first-line options 1, 2, 3
• PUVA is considered the least toxic systemic agent with a starting dose at 70% of the minimum phototoxic dose 1
• The 308-nm excimer laser allows selective targeting of localized resistant areas such as scalp and skin folds 1

Third-Line Treatment: Traditional Systemic Agents

When phototherapy is inadequate, use traditional systemic agents:

• For rapid response needed: Cyclosporine 3-5 mg/kg/day provides the most rapid onset of action (3 weeks), used in short 3-4 month "interventional" courses 1, 2

  • Requires regular monitoring of blood pressure, renal function, and lipid profile 2, 3

• Methotrexate has a response time of 2 weeks, FDA approved since 1972 1

  • Requires regular monitoring of complete blood count, liver function tests, and serum creatinine 2, 3

• Acitretin is another option for moderate-to-severe disease 2, 3

Fourth-Line Treatment: Biologic Therapies

For severe disease or inadequate response to traditional systemic agents:

• IL-17 inhibitors, IL-23 inhibitors, or IL-12/23 inhibitors are recommended 2, 3
• Adalimumab is effective for both skin and joint symptoms in psoriatic arthritis 1, 5
  • Dosing: 80 mg initial dose, then 40 mg every other week 5
• Infliximab demonstrates rapid and often complete disease clearance for generalized pustular psoriasis 1
  • Dosing: 5 mg/kg infused at weeks 0,2, and 6, then every 8 weeks thereafter 1

Combination Strategies to Enhance Efficacy

Adding topical therapy to systemic/biologic agents accelerates clearance:

• Add ultrahigh-potency (Class I) topical corticosteroid to standard dose etanercept for 12 weeks 1, 2
• Add calcipotriene/betamethasone to standard dose adalimumab for 16 weeks 1, 2
• Add topical calcipotriene to standard dose methotrexate 1, 2

Special Psoriasis Types

Guttate psoriasis:

• Often self-limiting and may require no active treatment or simple emollient 4
• Use low concentrations of tar and dithranol as it is less tolerant of topical treatment 4
• Ultraviolet B radiation may be especially helpful 4
• Investigate for streptococcal infection and treat with phenoxymethylpenicillin or erythromycin if present 4
• Consider tonsillectomy referral for repeated attacks after documented tonsillitis 4

Erythrodermic psoriasis:

• Oral cyclosporine 3-5 mg/kg/day due to rapid and impressive onset of action 1
• Mid-potency topical corticosteroids and emollients under occlusion may help restore barrier function, but systemic treatment is inevitably necessary 1

Psoriatic Arthritis Treatment

Escalate based on joint symptom severity:

• Mild joint symptoms: NSAIDs 2, 3
• Moderate-to-severe joint involvement: DMARDs (methotrexate, sulfasalazine, leflunomide) 2, 3
• Inadequate response to at least one DMARD: TNF inhibitors 2, 3

Critical Medications to AVOID

These medications can cause severe, potentially fatal deterioration:

• Systemic corticosteroids can cause severe disease flare during taper and should be absolutely avoided 1, 2
• Lithium, chloroquine, and mepacrine are associated with severe deterioration 1
• Beta-blockers, NSAIDs, and alcohol may worsen psoriasis 1

Common Pitfalls and Safety Considerations

• All commonly used systemic agents are absolutely contraindicated in pregnancy 2
• Commercial sunbeds are rarely effective and may cause premature skin aging and increased skin fragility 2
• Before starting biologics like adalimumab, screen for tuberculosis, hepatitis B, and active infections 5
• TNF blockers increase cancer risk, particularly lymphoma in RA patients and hepatosplenic T-cell lymphoma (often fatal) in young males on concurrent azathioprine or 6-mercaptopurine 5