Management of Phototherapy Side Effects

Acute Effects - Fiery Flare-ups

• Exaggerated, painful erythema resembling severe sunburn, occurring after phototherapy.
• Cause: Typically due to excessive UV dose, incorrect dosimetry, equipment malfunction, or concomitant photosensitizing medication.
• Onset: Usually within 2-12 hours post-exposure, peaking at ~24 hours.
• Management:
  • Immediately discontinue phototherapy.
  • Apply cool compresses and bland emollients liberally.
  • Prescribe topical corticosteroids (mild-to-moderate potency, e.g., hydrocortisone 1% cream).
  • Oral NSAIDs (e.g., ibuprofen) for pain and inflammation.
  • Antihistamines for pruritus if present.
  • Re-evaluate treatment protocol: verify dosimetry, patient factors. Restart at a significantly reduced dose (e.g., ↓ by 25-50% or revert to a previously well-tolerated dose) once resolved.
• Prevention: Accurate Minimal Erythema Dose (MED) testing, gradual dose increments, patient education on reporting early signs (tingling, burning).

⭐ Fiery flare-ups are phototoxic reactions (Type A adverse effect), which are dose-dependent and predictable, unlike photoallergic reactions that are immune-mediated and less common with standard phototherapy protocols.

Chronic Risks - Lasting Light Marks

• Photoaging: Wrinkles, solar elastosis, dryness, telangiectasias, lentigines ("age spots"). More pronounced with PUVA than NBUVB.
• Non-Melanoma Skin Cancer (NMSC):
  • SCC risk > BCC.
  • Factors: ↑ cumulative UV dose (PUVA > NBUVB), Fitzpatrick types I-II, prior skin cancer, immunosuppression.
  • Genital SCC (PUVA, inadequate shielding).

  ⭐ PUVA therapy significantly increases SCC risk, particularly with >200-250 treatments or high cumulative UVA doses (>1000-1500 J/cm²).

• Melanoma: Controversial; slight ↑ risk with high cumulative PUVA doses. NBUVB considered safer.
• PUVA Lentigines: Persistent, freckle-like hyperpigmented macules.
• Cataracts (PUVA): Due to psoralen; strict eye protection (during & 24h post-ingestion). envejecimiento cutaneo por puva

Modality Specifics - PUVA's Punch

• PUVA: Psoralen (oral/topical) + UVA. Oral 8-MOP taken 1.5-2 hrs pre-UVA.
• Acute Effects:
  • Nausea/Vomiting: Common, dose-related. Manage: antiemetics, take with food/milk.
  • Phototoxic Erythema ("PUVA burn"): Delayed onset, peaks 48-72 hrs. Careful dosimetry vital.
  • Pruritus: Can be intense.
• Chronic Effects (Cumulative Dose-Dependent):
  • Photoaging: Lentigines, xerosis, premature wrinkling.
  • ↑ Skin Cancer Risk: SCC > BCC, especially genital SCC.

    ⭐ Cumulative PUVA dose > 1000-2000 J/cm² significantly increases SCC risk.

  • Cataracts: Mandatory UV-protective eyewear for 24 hrs post-psoralen ingestion.
• 📌 PUVA's Chronic Punch: Photoaging, UV-induced Cancers, Visual (Cataracts), Accumulated dose is key.

Proactive Protection - Dodge The Damage

• Patient Counselling:
  • Inform about acute (erythema, pruritus, blistering) & chronic risks (photoaging, NMSC).
  • Emphasize strict adherence to treatment schedule & safety protocols.
  • Instruct on prompt reporting of adverse effects.
• In-Session Shielding:
  • Eyes: UV-opaque goggles (mandatory).
  • Genitals: Essential (especially males).
  • Face/Unaffected areas: Shield if not being treated.
• Post-Exposure Care:
  • Emollients: Apply liberally for dryness/pruritus.
  • Sunscreen: Broad-spectrum SPF >30; vital post-PUVA (for 24-48h).
  • Sun avoidance: Advise protective clothing. ⭐ > Patients on long-term PUVA therapy have a significantly increased risk of squamous cell carcinoma (SCC); regular dermatological surveillance is paramount.

High‑Yield Points - ⚡ Biggest Takeaways

• Erythema & pruritus: commonest acute effects. Manage: emollients, topical steroids, antihistamines, dose adjustment.
• Herpes simplex reactivation: consider prophylactic antivirals if history positive.
• Carcinogenesis: PUVA ↑ SCC risk; NB-UVB has lower NMSC risk. Regular skin surveillance vital.
• PUVA-specific: Nausea (psoralen with food), hepatotoxicity (monitor LFTs), cataracts (UV eye protection mandatory).
• Severe reactions (e.g., blistering): stop phototherapy. Chronic: photoaging (advise sun protection).