What are the treatment options for psoriasis?

Treatment Options for Psoriasis

The treatment of psoriasis should follow a stepwise approach based on disease severity, with topical agents being first-line for limited disease and systemic therapies reserved for more severe or refractory cases. 1

Assessment of Psoriasis Severity

Before initiating treatment, proper assessment is crucial:

• Disease severity evaluation:

  • Patient's perception of disability ("need for treatment")
  • Objective assessment of extent (body surface area) and severity
  • Body surface area < 5%: Limited disease
  • Body surface area ≥ 5%: Moderate-to-severe disease
  • Special sites (face, genitals, hands, feet, scalp) may warrant more aggressive therapy despite limited area 1

• Factors that may worsen psoriasis:

  • Alcohol
  • Beta-blockers
  • Non-steroidal anti-inflammatory drugs
  • Lithium, chloroquine, and mepacrine (can cause severe deterioration) 1

Treatment Algorithm

1. Limited Disease (< 5% BSA)

First-line: Topical Therapies

• Coal tar preparations:

  • Extremely safe, can be used as refined products or cruder extracts
  • Start with 0.5-1.0% crude coal tar in petroleum jelly
  • Increase concentration every few days to maximum 10% 1

• Dithranol (anthralin):

  • Requires patient education about side effects (irritancy and staining)
  • Start at 0.1-0.25% concentration
  • Increase in doubling concentrations as tolerated
  • Use with caution on face, flexures, and genitalia 1

• Topical corticosteroids:

  • Guidelines for use:
    • Regular clinical review
    • No unsupervised repeat prescriptions
    • ≤ 100g of moderately potent preparation per month
    • Alternate with other treatments periodically
    • Very potent or potent preparations only under dermatological supervision 1

• Other topical agents:

  • Vitamin D analogs (calcipotriene)
  • Retinoids (tazarotene) 2

2. Moderate-to-Severe Disease (≥ 5% BSA or Refractory to Topicals)

First-line: Phototherapy

• UVB phototherapy:

  • Should not be used as continuous maintenance unless alternatives have failed 1

• PUVA (Psoralens + UVA):

  • First-choice systemic treatment with least toxicity
  • Contraindications: pregnancy, cataracts, age <18, previous skin malignancy
  • Requires eye protection and genital shielding
  • Response typically within 4 weeks 1

• Commercial sunbeds (UVA):

  • Not recommended due to limited efficacy and side effects 1

Second-line: Systemic Agents

Indications for systemic treatment:

• Failure of adequate trial of topical treatment
• Repeated hospital admissions for topical treatment
• Extensive disease in elderly or infirm people
• Generalized pustular or erythrodermic psoriasis
• Severe psoriatic arthropathy 1

Traditional systemic agents:

• Methotrexate:

  • Response within 2 weeks
  • Contraindications: pregnancy, breastfeeding, wish to father children, liver damage, blood disorders
  • Requires contraception and monitoring 1

• Cyclosporine:

  • Response within 3 weeks
  • Contraindications: abnormal renal function, uncontrolled hypertension, malignancy
  • Requires blood pressure and renal function monitoring 1

• Retinoids (etretinate/acitretin):

  • Response within 6 weeks
  • Contraindications: pregnancy or wish to conceive within 2 years of stopping
  • Requires lipid monitoring 1

• Other agents:

  • Hydroxyurea
  • Azathioprine 1

Biologic agents:

• For moderate-to-severe psoriasis unresponsive to traditional therapies
• Adalimumab (TNF blocker):
  • Dosing: 80 mg initial dose, followed by 40 mg every other week starting one week after initial dose
  • Boxed warnings for serious infections and malignancy
  • Monitor for tuberculosis and opportunistic infections 3
• Other biologics:
  • Anti-IL17 agents (most effective)
  • Anti-IL23 agents
  • Anti-TNF agents 4

3. Special Situations

Guttate psoriasis:

• Often follows streptococcal infection
• Treat underlying infection with penicillin or erythromycin
• Consider tonsillectomy for recurrent cases 1

Pustular psoriasis of palms and soles:

• Moderately potent topical corticosteroids
• Consider systemic retinoids for resistant cases 1

Generalized pustular or erythrodermic psoriasis:

• Hospital admission and systemic agents 1

Rotational Therapy Approach

For patients requiring long-term treatment, consider rotational therapy:

• Use each treatment modality for 1-2 years before switching to another
• This minimizes cumulative toxicity of any single agent
• Allows effective treatments to be maintained for many years 5

Important Considerations

• Pregnancy: All commonly used systemic agents are contraindicated
• Women of childbearing age: Explain risks and necessity for contraception
• Combination therapy: Use with extreme caution as toxicities are at least additive
• Monitoring: Regular follow-up and appropriate laboratory testing based on therapy
• Specialist referral: Patients with severe psoriasis requiring systemic agents should be under dermatologist supervision 1

Remember that while there is no cure for psoriasis, treatment aims to induce remission or make the disease tolerable for the patient. The treatment approach must be tailored based on disease severity, affected areas, and patient factors.