What are the guidelines for using home narrow-band Ultraviolet B (UVB) therapy in patients with psoriasis?

Guidelines for Home Narrow-band UVB Therapy in Psoriasis

Home narrow-band UVB (NB-UVB) phototherapy is an effective and appropriate maintenance option for psoriasis patients who have achieved clearance with in-office phototherapy but face logistical challenges with continued clinic visits. 1

Indications for NB-UVB Therapy

• First-line phototherapy option for moderate to severe plaque and guttate psoriasis 1
• Appropriate for patients with:
  • Significant body surface area involvement (typically >5% BSA)
  • Psoriasis not adequately controlled with topical treatments
  • Need for a treatment option that avoids systemic immunosuppression

Advantages of NB-UVB over PUVA

• Lower long-term photocarcinogenic risk
• No need for oral medication before treatments
• No need for photoprotective eyewear between treatments
• Safe to use during pregnancy 1
• Avoids drug interactions and systemic side effects

Home vs. Office-Based NB-UVB

When to Consider Home NB-UVB

Home NB-UVB is particularly valuable for:

• Patients who have achieved clearance with in-office therapy and need maintenance
• Those who are geographically isolated from phototherapy centers
• Patients unable to attend 2-3 weekly in-office sessions due to work or other commitments 1
• Patients with stable disease who understand proper usage protocols

Safety Considerations for Home NB-UVB

• Patient education is essential before initiating home therapy 1
• Equipment must be certified with accurate dosimetry systems 2
• Patients should receive proper training on:
  • Operating the equipment
  • Recognizing and managing side effects
  • Appropriate eye protection during treatments
  • Proper skin protection for areas not requiring treatment 3

Treatment Protocol for NB-UVB

Initial Treatment Phase

• Starting doses should be based on skin type:

  • Skin type II: 180-200 mJ/cm²
  • Skin type III: 200-250 mJ/cm²
  • Skin type IV: 250-300 mJ/cm²
  • Skin type V-VI: 300-400 mJ/cm² 4

• Frequency: 3 times per week is optimal for clearing (higher clearance rates of 62% vs. 17% with <2 sessions/week) 4, 5

• Duration: Typically requires 20-30 treatments for significant improvement 1

Dose Increments

• Fixed increments based on skin type are safer than percentage-based increases:
  • Skin type II: 30 mJ/cm²
  • Skin type III: 40 mJ/cm²
  • Skin type IV: 50 mJ/cm²
  • Skin type V-VI: 60-150 mJ/cm² 4

Maintenance Phase

• Once clearance is achieved, frequency can be reduced to 1-2 times weekly
• No strong evidence supports continuous maintenance therapy, but it may be considered for quickly recurrent disease 1
• The goal is to use the lowest effective dose with the least toxic therapy 1

Monitoring and Safety

• Patients should be monitored for:

  • Erythema (redness)
  • Burning
  • Itching
  • Long-term skin changes

• Sun protection recommendations:

  • Use physical sunscreens with zinc oxide/titanium dioxide (SPF 30-50+)
  • Apply sunscreen to areas not requiring treatment
  • Avoid photosensitizing medications when possible 3

• Long-term monitoring:

  • Annual skin examinations recommended for patients receiving >150 phototherapy sessions 2
  • Consider setting a lifetime maximum of 250 NB-UVB sessions (similar to PUVA guidelines) 2

Combination Therapies

• NB-UVB can be combined with:
  • Topical corticosteroids
  • Vitamin D analogs (though synergistic effects are less pronounced)
  • Retinoids (acitretin) - can enhance efficacy and reduce required UV exposure 1, 2

Efficacy Expectations

• 60-90% of patients achieve complete or near-complete clearance within 20-40 sessions 2
• NB-UVB leads to approximately 25% reduction in steroid cream use and 30% reduction in vitamin-D product use for up to 12 months following treatment 6
• Better results are typically seen with guttate and nummular psoriasis compared to large plaque psoriasis 2

Contraindications and Cautions

• History of melanoma or multiple non-melanoma skin cancers
• Photosensitizing medications
• Photosensitive disorders
• History of arsenic exposure or ionizing radiation
• Inability to follow safety protocols

Home NB-UVB therapy represents an effective, convenient option for appropriate psoriasis patients, offering similar efficacy to in-office treatment while improving treatment adherence through greater accessibility.