What are the treatment options for Polymorphic Light Eruption (PMLE)?

Treatment Options for Polymorphic Light Eruption (PMLE)

Photohardening/desensitization with narrowband UVB or PUVA therapy is the most effective preventive approach for polymorphic light eruption, with PUVA being considered if UVB has failed or previously triggered eruptions. 1

First-Line Prevention and Treatment

Phototherapy

• Narrowband UVB (NB-UVB): First-line phototherapy option

  • Administered in early spring (in temperate climates)
  • Typically given 2-3 times weekly for 12-20 treatments
  • Success rate: 89% of patients report good to moderate improvement 2

• PUVA (Psoralen plus UVA): Second-line phototherapy option

  • Consider when:
    • NB-UVB has failed
    • NB-UVB previously triggered eruptions
    • Other practical issues exist 2
  • Administration:
    • 2-3 times weekly for 12-20 treatments
    • Success rate: 88-92% of patients report good to moderate improvement 2
  • Caution: Risk of provoking PMLE is high with initial exposures (12-50% of treatment courses) 2

Managing Provocation Risk During Phototherapy

• Apply potent topical steroids after each exposure
• Use lower dose increments if provocation occurs
• Consider oral prednisolone (40-50 mg) for first 2 weeks of phototherapy 2, 1
• Timing is critical:
  • Too early: photoprotective effect may subside by mid-summer
  • Too late: patient may have already suffered an eruption 2

Treatment of Acute Episodes

Topical Treatments

• Topical corticosteroids: First-line for active lesions 1, 3
  • Apply to affected areas promptly when symptoms appear
  • Potent formulations are most effective

Systemic Treatments

• Systemic corticosteroids: For severe or extensive eruptions 1, 3
• Antihistamines: Helpful for controlling pruritus 1, 4

Additional Preventive Measures

Sun Protection

• Broad-spectrum sunscreens: High UVA protection is crucial
  • Studies show sunscreens with effective UVA and UVB filters can successfully prevent PMLE development 5
  • Apply 30 minutes before sun exposure

Antioxidants

• Topical antioxidant formulations combined with sunscreens show superior efficacy compared to sunscreens alone 6, 4
  • Formulations containing alpha-glucosylrutin and vitamin E are particularly effective 6

Long-term Management Considerations

• Annual desensitization with PUVA is not usually recommended due to long-term skin cancer risk 2, 1
• Post-phototherapy advice includes continued natural sunlight exposure to maintain resistance throughout summer 2
• For severe refractory cases, immunosuppressive drugs may be considered 4

Common Pitfalls and Caveats

• Timing of phototherapy is critical for effectiveness and to minimize side effects
• PUVA has higher risk of side effects (erythema, pruritus) compared to NB-UVB
• Regular application of sunscreen under everyday conditions may not provide the same level of protection as tested under standardized conditions 5
• Patients should be counseled about the chronic, recurrent nature of PMLE and the importance of preventive measures