Actinic Keratosis

Key Features

• Actinic keratoses are considered premalignant, but only 1:1000 lesions/year progresses to become squamous cell carcinoma

Clinical Findings

• Actinic keratoses are small (0.2–0.6 cm) macules or papules—flesh-colored, pink, or slightly hyperpigmented—that feel like sandpaper and are tender to palpation

• They occur on sun-exposed parts of the body in persons of fair complexion

Diagnosis

• Clinical

• Differential diagnosis

  • Squamous cell carcinoma

  • Bowen disease (squamous cell carcinoma in situ)

  • Nonpigmented seborrheic keratosis

  • Psoriasis

  • Seborrheic dermatitis

  • Seborrheic keratosis

  • Paget disease

Treatment

• Liquid nitrogen

  • Rapid method of eradication

  • Lesions crust and disappear in 10–14 days

• Field treatment

  • Defined as treatment over an area, rather than targeted treatment to one lesion

  • Can be considered in patients with multiple lesions in one region

  • Fluorouracil cream is the most effective topical agent

  • Imiquimod, ingenol mebutate, and photodynamic therapy are also effective

• Lesions that persist should be evaluated for possible biopsy