Skin & Soft Tissue: Actinic Keratosis (AK)

Definition

• Proliferation of Epidermal Keratinocytes
• Also Known as “Solar Keratosis”

Malignancy

• Premalignant Lesion
• May Progress to Squamous Cell Carcinoma
• Low Risk of Malignant Transformation (0.03-20% Risk Per Year)
• A Large Percentage (60%) of SCC’s Arise from Preexisting AK’s

Risk Factors

• Fair Skin
• Sun Exposure/Ultraviolet Radiation
• Male Sex
• Increasing Age

Presentation

• Erythematous, Scaly Papules or Plaques
• May Have a “Cutaneous Horn” – Projection of Compacted Keratin
• Most Common on Sun-Exposed Areas (Face, Neck, Balding Scalp & Extremities)
• “Field Cancerization” – Multiple Lesions with Surrounding Areas of Chronic Actinic Damage
  • Increases Risk of Developing SCC

Diagnosis

• Mostly Clinical (Based on History and Physical Exam)
• May Consider Skin Biopsy to Rule Out Malignancy

Treatment

• Single/Few Isolated Lesions: Liquid Nitrogen Cryotherapy
  • Thick Lesions May Require Longer Freezing Time or Repeated Treatments
  • If Repeatedly Fails: Consider Excision or Curettage with Electrodessication
• Multiple Lesions/Field Cancerization: Topical Therapies or Photodynamic Therapy
  • Topical Agents: Fluorouracil or Imiquimod
  • Photodynamic Therapy – Photosensitizing Agent Applied Followed by Illumination with a Set Amount of Light
  • May Consider Sequential Cryotherapy of Discrete Lesions Prior to Topical Therapies
  • Other Options:
    • Topical Ingenol Mebutate – Possibly Increased Risk of SCC
    • Topical Diclofenac
    • Topical Retinoids
    • Topical Tirbanibulin
    • Dermabrasion
    • Chemical Peels