HemeOnc

Actinic Keratoses

search

Actinic Keratoses, Actinic Keratosis

  • Epidemiology
  1. Most common premalignant skin lesion
    1. Responsible for 60% of Squamous Cell Carcinoma involving the skin
  2. Prevalence: White skin (increases with age)
    1. Age 20-29: 10%
    2. Age 80-89: 75%
  • Pathophysiology
  1. Superficial keratotic tumor
  2. Previously considered distinct premalignant changes
  3. Now thought to be very early Squamous Cell Carcinomas
    1. Ortonne (2002) Br J Dermatol 146:20-3 [PubMed]
  • Risk Factors
  1. Fair-skinned, blue-eyed persons
  2. Living in sunny climate
  3. Cummulative extensive Sun Exposure
  4. Older persons
  • Symptoms
  1. Typically asymptomatic
  2. May be pruritic or burning
  • Signs
  1. Characteristics: Rough Scaly patches
    1. Discrete, circumscribed
    2. Verrucous or keratotic
    3. White scale or rough patch
    4. Red-brown, pink or skin-colored Macule or Papule
    5. Often recurs after patient "picks off" scale
    6. Vary in size from millimeters to centimeters (typically 2-6 mm in size)
  2. Distribution: Sun exposed areas
    1. Face and neck
      1. Left more common (Car driver's window side)
    2. Dorsal hands
    3. Forearms
  • Diagnosis
  1. Diagnosis by "feel": Rough
  2. Biopsy is rarely indicated
  • Management
  • Procedures
  1. Cryotherapy with Liquid Nitrogen
    1. Debride hyperkeratotic lesions first
    2. Freeze, slowly thaw and then refreeze
    3. Efficacy increases with duration of freeze time
      1. Freeze 5 seconds: 39% cure rate
      2. Freeze 20 seconds: 83% cure rate
  2. Curettage
    1. Infiltrate area with local anesthetic
    2. Consider for hyperkeratotic lesions
    3. Adjuncts
      1. Trichloroacetic acid (TCA) before curettage
      2. Electrosurgery post-curettage to destroy residual tissue
  3. Photodynamic therapy
    1. Photosensitizer applied to skin followed by exposure to specific light source
    2. Protocols
      1. Aminolevulinic Acid (Levulan Kerastick): Exposure to blue light after 14 hours
      2. Methyl aminolevulinate (Metvixia): Exposure to red light after 3 hours
  1. Indicated when numerous lesions (e.g. >15 lesions present)
  2. Topical 5-Flourouracil (5-FU)
    1. Preparations
      1. Fluorouracil cream 5% (Efudex)
      2. Fluorouracil cream 1% (Fluoroplex)
      3. Fluorouracil microspore cream 0.5% (Carac)
    2. Adverse effects
      1. Healing may require 2 months
      2. Photosensitivity (protect from direct sun)
      3. Dryness, erythema, irritation, crusting, pealing and even disfigurement on the face
        1. Irritation more common with 5% cream; 0.5% appears better tolerated (but less effective)
        2. May apply cool compresses or petrolatum to soothe skin
    3. Technique
      1. Use twice weekly for 2-4 weeks until marked inflammation and lesion crusts over
      2. Consider 0.5% cream for one week prior to Cryotherapy
      3. Wait 30 min before applying Sunscreen or makeup
    4. Efficacy
      1. 5-fluorouracil 5% cream more effective, less re-treatement than Imiquimod, ingenol and Phototherapy
        1. 5-FU 5% cream is also among the most cost effective options (<$100 per course)
        2. However lower concentrations (e.g. Carac) having more limited efficacy, at 10 times the cost
        3. Jansen (2019) N Engl J Med 380:935-46 [PubMed]
  3. Topical Diclofenac 3% gel in 2.5% hyaluronic acid (Solaraze)
    1. Technique: Apply twice daily for 90 days
    2. Efficacy
      1. Complete resolution in 50% of cases
      2. Less effective than Imiquimod (Aldara), 5-Fluorouracil (5-FU) or ingenol (Picato), yet >$600 per course
    3. Adverse Effects
      1. Skin inflammation (Local irritation, dryness and Pruritus
        1. Less irritating than Imiquimod (Aldara), 5-Fluorouracil (5-FU) or ingenol (Picato)
    4. Reference
      1. Rivers (1997) Arch Dermatol 133:1239-42 [PubMed]
  4. Imiquimod 5% Cream (Aldara)
    1. Applied 3-4 times weekly at bedtime and wash off in AM; use for up to 16 weeks
    2. Efficacy
      1. Complete response in up to 57% of patients
      2. Partial response (75% reduction) in up to 72% of patients
    3. Adverse effects
      1. Cosmetic outcomes not studied
      2. Severe erythema (80%)
      3. Severe erosions (40%)
    4. References
      1. Stockfleth (2002) Arch Dermatol 138:1498-502 [PubMed]
  5. Ingenol mebutate (Picato gel)
    1. Technique: Total course is 2-3 days
      1. Picato 0.05%: Apply to torso or extremities for 2 days
      2. Picato 0.015%: Apply to face or scalp for 3 days
    2. Adverse effects
      1. Skin irritation (erythema, flaking or crusting)
    3. Efficacy
      1. Similar to Imiquimod and 5-Fluorouracil, but very expensive ($1000)
  6. Chemical Peels for face (applied by dermatology)
    1. Similar efficacy to fluorouracil
    2. Preparations
      1. Jessner's Solution (Resorcinol, Lactic Acid, Salicylic acid)
      2. Trichloroacetic acid 35% (Tri-Chlor)
    3. References
      1. Lawrence (1995) Arch Dermatol 131:176-81 [PubMed]
  • Management
  • Adjunctive measures
  1. Niacinamide
    1. Indicated if Actinic Keratosis patient with 2 or more Nonmelanoma Skin Cancers
    2. Decreases risk of new Actinic Keratosis lesions and Nonmelanoma Skin Cancers
    3. Dose: 500 mg orally twice daily ($5/month)
  • Prevention
  1. See Sun Exposure (lists general preventive measures)
  2. See Sunscreen
  • Course
  1. Spontaneous resolution in 25% of lesions over 12 months
  2. Progression to squamous cell cancer: 6-10% over 10 years
  3. Higher risk of Squamous Cell Carcinoma progression in thick tumors (especially on scalp)
  • References