Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 6-18: Miscellaneous Scaling Dermatoses + Key Features Download Section PDF Listen +++ ++ Actinic keratoses are considered premalignant, but only 1:1000 lesions/year progresses to become squamous cell carcinoma + Clinical Findings Download Section PDF Listen +++ ++ 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 Download Section PDF Listen +++ ++ Clinical Differential diagnosis Squamous cell carcinoma Bowen disease (squamous cell carcinoma in situ) Nonpigmented seborrheic keratosis Psoriasis Seborrheic dermatitis Seborrheic keratosis Paget disease + Treatment Download Section PDF Listen +++ ++ 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