Can ultraviolet (UV) light help reduce inflammation of the skin?

UV Light Therapy for Skin Inflammation

Ultraviolet (UV) light therapy can effectively reduce skin inflammation in certain inflammatory skin conditions, but should be used selectively due to potential long-term risks including skin cancer. 1

Types of UV Therapy for Inflammatory Skin Conditions

Phototherapy using UV radiation is a well-established treatment option for several inflammatory skin conditions. The main types include:

• Narrowband UVB (NB-UVB):

  • Most commonly used form of phototherapy 1
  • Wavelength: 311-313 nm
  • Mechanism: Decreases keratinocyte proliferation, reduces Langerhans cells, down-regulates Th17 cells, induces T-cell apoptosis 2

• UVA1:

  • Wavelength: 340-400 nm
  • Used in some inflammatory conditions 1

• PUVA (Psoralen plus UVA):

  • Combines UVA with photosensitizing psoralen medication
  • Higher efficacy but also higher risk profile 1

Effectiveness for Inflammatory Skin Conditions

UV therapy has demonstrated efficacy in treating several inflammatory skin conditions:

1. Atopic Dermatitis (Eczema):

   • NB-UVB may provide greater reduction in physician-assessed signs compared to placebo after 12 weeks of treatment 3
   • May increase the number of people reporting reduced itch 3

2. Psoriasis:

   • Well-established treatment option 2
   • NB-UVB is recommended as first-line phototherapy option by the American Academy of Dermatology 2
   • PUVA may be more effective for refractory cases but carries higher risks 2

Treatment Protocol Considerations

• Frequency: Typically 2-3 times per week for 10-14 weeks 1
• Duration: Treatment courses vary based on condition and response
• Monitoring: Regular assessment for effectiveness and side effects
• Combination therapy: Often used with topical treatments for enhanced efficacy 1

Safety Considerations and Adverse Effects

Short-term side effects:

• Erythema (sunburn-like reactions)
• Pruritus (itching)
• Heat intolerance
• Phototoxic reactions 1

Long-term risks:

• Skin cancer risk: Well-established for PUVA, less concerning but still present with other modalities 1
• Photoaging: Premature skin aging with chronic exposure 4
• Immunosuppression: Local and systemic effects 4

Patient Selection and Contraindications

UV therapy should be avoided or used with extreme caution in patients with:

• History of melanoma or high risk for skin cancer
• Photosensitivity disorders
• Lupus erythematosus
• Xeroderma pigmentosum 2

Practical Limitations

• Accessibility: Requires significant time commitment (2-3 weekly visits)
• Travel burden: May not be feasible depending on distance to treatment centers
• Insurance coverage: Variable, with some plans requiring substantial co-pays 1
• Home phototherapy: Can increase accessibility but requires proper training and supervision 1

Clinical Decision Algorithm

1. Assess condition severity and previous treatments:

   • Consider phototherapy when topical treatments are insufficient
   • Evaluate patient's ability to commit to treatment schedule

2. Select appropriate UV modality:

   • NB-UVB: First-line for most inflammatory conditions
   • UVA1: Consider for deeper inflammatory processes
   • PUVA: Reserve for refractory cases due to higher risk profile

3. Monitor treatment response:

   • Assess improvement in inflammation after 4-6 weeks
   • Continue if beneficial; discontinue if inadequate response or adverse effects

4. Long-term management:

   • Limit lifetime exposure, especially with PUVA
   • Consider maintenance therapy for chronic conditions
   • Regular skin examinations to monitor for skin cancer

While UV therapy can be effective for reducing skin inflammation, the decision to use it must carefully balance potential benefits against risks, particularly the long-term risk of skin cancer with extensive treatment.