What is the best treatment for actinic keratosis in an elderly patient?

Treatment of Actinic Keratosis in an Elderly Patient with Multiple Lesions

For an 89-year-old male with multiple actinic keratoses on the scalp, face, and arms, field treatment with 5-fluorouracil (5-FU) is strongly recommended as first-line therapy, with cryosurgery for thicker individual lesions. 1

Initial Assessment and Treatment Selection

When evaluating treatment options for this patient, several factors must be considered:

1. Distribution and extent of lesions:

   • Multiple rough scaly patches with erythematous bases on scalp and face
   • Sandpaper texture on dorsal forearms
   • This pattern suggests field cancerization requiring both field and lesion-directed treatment

2. Patient-specific factors:

   • Advanced age (89 years)
   • History of significant sun exposure (Texas residence)

Recommended Treatment Algorithm:

For Field Treatment (Multiple Lesions):

1. First-line: 5-Fluorouracil (5-FU)

   • Strong recommendation with moderate quality evidence 1
   • Dosing options:
     • 5% cream applied twice daily for 2-4 weeks
     • 0.5% cream applied once daily for 1-4 weeks 2
   • Highly effective with complete clearance in approximately 70% of lesions for up to 12 months 2

2. Alternative options if 5-FU is not tolerated:

   • Imiquimod 5% cream (strong recommendation, moderate evidence) 1

     • Applied 2-3 times per week for 16 weeks
     • Complete clearance rates of 44-46% 3

   • Tirbanibulin 1% ointment (strong recommendation, high evidence) 1

     • Applied once daily for 5 consecutive days
     • Complete clearance rate of 49% at day 57
     • Advantage: Very short treatment duration

For Individual Thicker Lesions:

1. Cryosurgery (strong recommendation) 1
   • Particularly effective for thicker lesions (69% response vs 52% with PDT) 1
   • Duration of freeze:
     • 5-20 seconds for most lesions

     • 20 seconds for thicker lesions on scalp and face (83% cure rate) 1

Treatment Considerations by Anatomic Location

Face and Scalp:

• 5-FU field treatment followed by cryosurgery for persistent lesions 1, 2
• Photodynamic therapy (PDT) is a conditional alternative with 70-89% clearance rates 2

Arms (Dorsal Forearms):

• 5-FU field treatment (may require extended treatment period) 2
• Diclofenac 3% gel is a conditional alternative (applied twice daily for 60-90 days) 1

Managing Treatment Side Effects

• 5-FU side effects: Soreness, redness, crusting

  • Can be managed with:
    • Reduced application frequency
    • Short treatment breaks
    • Emollients
    • Topical steroids for severe reactions 2

• Cryotherapy side effects: Blistering, pigmentary changes, scarring

  • More pronounced in darker skin types

Follow-up and Monitoring

• Complete healing may take 1-2 months after treatment completion 2
• Any lesions that fail to respond to appropriate therapy require biopsy to rule out squamous cell carcinoma 1, 2
• Regular follow-up is essential to evaluate treatment success and detect new lesions

Important Considerations

• UV protection is strongly recommended to prevent new lesions 1
• Combination therapy (e.g., 5-FU followed by cryosurgery) is conditionally recommended over cryosurgery alone for resistant lesions 1
• For this elderly patient, the treatment plan should balance efficacy with tolerability, considering the extensive distribution of lesions

Treatment Pitfalls to Avoid

1. Undertreating field cancerization: Treating only visible lesions while ignoring subclinical damage
2. Overaggressive treatment: May lead to unnecessary discomfort in elderly patients
3. Failure to biopsy non-responsive lesions: Any lesion that persists after appropriate treatment requires histological evaluation
4. Neglecting sun protection: Essential to prevent recurrence and new lesions

For this 89-year-old patient with multiple actinic keratoses, a combination approach of field treatment with 5-FU and targeted cryotherapy for thicker lesions represents the most effective strategy based on current evidence.