Actinic Keratosis

Snapshot

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  • A 60-year-old man with multiple “sun spots,” or solar lentigos, comes to the dermatologist for his annual skin exam. He complains of several rough patches on his cheeks that has been there for a year. They feel like sandpaper. He is a gardener and often spent hours under the sun.

Introduction

  • Keratotic, pre-malignant lesions 
  • Epidemiology
    • common in fair-skinned individuals
    • common in elderly patients
    • results from significant lifetime sun exposure 
      • keratinocyte damage
  • May lead to squamous cell carcinoma 

Presentation

  • Symptoms
    • typically asymptomatic
  • Physical exam 
    • thin, adherent scale that is transparent or yellow
    • rough, “sand-paper” texture
    • may see some telangiectasias
    • frequently on sun-exposed areas
  • face, head, neck, dorsal hands, ears

Evaluation

  • Skin biopsy
    • dysplastic epidermis with keratinocyte atypia
  • no invasion into dermis

Differential

  • Squamous cell carcinoma 
  • Actinic cheilitis
  • Lentigo maligna
  • Photoaging 
    • presents as rough texture, abundant wrinkles, and diffuse mottled pigmentation
  • seen on histology as flattening of dermal papillae with basophilic depositions.

Treatment

  • Lifestyle modification
    • avoid sun exposure
    • use sunscreen
  • Surgical
    • liquid nitrogen (cryotherapy) = most common treatment
  • Pharmacological
  • topical 5-fluorouracil

Prognosis, Prevention, and Complications

  • Prognosis
    • typically slow-growing and persistent if untreated
  • Prevention
    • avoid sun exposure
    • use sunscreen
  • Complications
    • risk of progression to squamous cell carcinoma