What is the recommended treatment for pustular psoriasis?

Treatment of Pustular Psoriasis

Acitretin is recommended as the first-line systemic therapy for pustular psoriasis, with biologics like infliximab reserved for severe or refractory cases. 1

Types of Pustular Psoriasis

Pustular psoriasis presents in several forms:

1. Generalized pustular psoriasis (GPP): Characterized by widespread sterile pustules on erythematous skin, often with systemic symptoms
2. Localized pustular psoriasis: Affects palms and soles (palmoplantar pustulosis)
3. Acropustulosis (acrodermatitis continua of Hallopeau): Affects terminal phalanges and nails

Treatment Algorithm

First-Line Therapy

• Acitretin: Recommended at 0.1-1 mg/kg/day 1
  • Particularly effective for pustular variants
  • Response typically seen within 3 weeks for pustular forms
  • Advantages: Non-immunosuppressive, effective for pustular variants
  • Caution: Absolute contraindication in women of childbearing potential (teratogenic for up to 3 years)

Second-Line Options

• Cyclosporine: Effective for short-term crisis therapy 1

  • Dosing: 2.5-5.0 mg/kg/day
  • Rapid onset of action
  • Limitation: Not suitable for long-term use due to nephrotoxicity

• Methotrexate: Consider if acitretin is contraindicated

  • Dosing: 10-15 mg weekly
  • Requires folic acid supplementation and monitoring

Severe or Refractory Cases

• TNF inhibitors:

  • Infliximab: Most evidence for GPP 1

    • Dosing: 5 mg/kg IV at weeks 0,2,6, then every 8 weeks
    • Rapid response in severe cases

  • Etanercept: Effective at 50 mg twice weekly (not at 25 mg) 1

    • Can maintain response for up to 48 weeks

• IL-36 receptor antagonist:

  • Spesolimab: Emerging therapy showing promising results for severe GPP flares 2
    • Particularly effective for cases resistant to conventional treatments

Combination Approaches

• Acitretin + Narrowband UVB: Synergistic effect for plaque and pustular psoriasis 1

  • Allows reduction in dosing of both agents
  • Suitable for patients old enough to cooperate with therapy

• Infliximab + Methotrexate: Recommended for severe, unresponsive pustular psoriasis 1

Special Considerations

Localized Pustular Psoriasis (Palms and Soles)

• Topical therapy: Moderately potent corticosteroids (British National Formulary grade III) 1
• Additional options: Topical coal tar and dithranol
• Avoid TNF antagonists: Evidence suggests lack of benefit and potential to trigger palmoplantar pustulosis 1

Acropustulosis (Acrodermatitis Continua)

• TNF antagonists: Consider etanercept, infliximab, or adalimumab 1
  • Multiple case reports show significant benefit
  • Important option for this rare but disabling condition

Monitoring and Adverse Effects

• Acitretin:

  • Monitor for mucocutaneous effects (skin/mucous membrane dryness)
  • Check lipid profile (transient hyperlipidemia may occur)
  • Pregnancy testing and contraception counseling essential

• Cyclosporine:

  • Regular monitoring of blood pressure and renal function
  • Limit duration to prevent irreversible nephrotoxicity

• Biologics:

  • Screen for infections and tuberculosis before initiation
  • Monitor for injection site reactions

Treatment Pitfalls to Avoid

1. Inappropriate use of topical therapy alone for generalized pustular psoriasis
2. Prolonged corticosteroid use which can trigger rebound flares upon withdrawal
3. Using TNF inhibitors for palmoplantar pustulosis where they may be ineffective or worsen disease
4. Inadequate contraception counseling when prescribing acitretin to women
5. Delayed escalation to biologics in severe or life-threatening cases

Remember that generalized pustular psoriasis can be life-threatening and may require hospitalization for initial management. Prompt and aggressive therapy is essential to reduce morbidity and mortality.