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Case Note

Case Note: Crusty Lesions


A 72-year-old woman presents with a 3-month history of several new lesions on the dorsal hands. She has no prior history of skin cancer, but does have a history of extensive sun exposure during her youth and early adult life.

Initial evaluation

  • She reports increasing scale and crusting of the lesions, noting that the crusting sloughs intermittently (but then recurs)
  • No prior history of skin cancer
  • A complete skin exam reveals no additional suspicious lesions

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Enter your diagnosis


  • A diagnosis of actinic keratoses (AK) is rendered

Further to the case in question, general evaluation strategy for AK is provided below.

Assess patient's history for factors that increase risk of developing AK and/or non-melanoma skin cancer:

  • Cumulative ultraviolet radiation (sunlight, artificial light) exposure
  • Arsenic exposure
  • History of immunocompromised status (HIV/ AIDS, solid organ or bone marrow transplant, immunosuppressive therapy)
  • Genodermatoses involving photosensitivity and accelerated photo-aging and/or cutaneous neoplasms (xeroderma pigmentosum, albinism, Rothmund-Thomson syndrome)

Numerous AKs on sun-damaged skin are characterized by ill-defined hyperkeratotic erythematous papules or plaques. AKs are commonly very thin and may lack erythema, and are best discerned clinically by palpation rather than visual inspection.

AKs can present with a cutaneous horn, a column of hyperkeratotic scale lying over an ill-defined erythematous scaly papule.

Initial Treatment

  • Liquid nitrogen spray (thaw time 8 seconds)
  • Liquid nitrogen can be applied by:
    • Application by cryo spray; use of a specialized plastic cone or otoscope piece may aid in focusing the spray at the base of the lesion
    • Application of cotton swab dipped in liquid nitrogen to lesion
    • Application of metal forceps dipped in liquid nitrogen to base of lesion
  • Counseling of sequelae and skin care after treatment
  • Follow-up in 6-8 weeks

Follow-up evaluation strategy

At 8 weeks:

  • Lesion has been completely eradicated, with only faint macular erythema; here, no induration or scale present
  • Photoprotection counseling
  • Follow-up for skin exam in 6 months

General discussion

AKs typically present as scaly, erythematous papules or plaques on sun-exposed areas, and are the most common epithelial precancerous skin lesions. Clinical variants of AKs include: erythematous, atrophic, hyperkeratotic, pigmented and lichenoid forms. AKs on the lower lip are termed actinic cheilitis. Treatment is necessary because approximately 5-15% of lesions may progress to non-melanoma skin cancer (NMSC).

Three strategies for treatment are most frequently used:

  1. Physical destruction
  2. Topical chemotherapy
  3. Local stimulation of the immune system

Therapy is determined by location (face, scalp, forearms or legs), extent and number (few versus multiple) of the lesions.

Further reading

Braathen LR, et al. Guidelines on the use of photodynamic therapy for nonmelanoma skin cancer: an international consensus. International Society for Photodynamic Therapy in Dermatology, 2005. J Am Acad Dermatol 2007;56:125-43.

Cowen EW, et al. Chronic phototoxicity and aggressive squamous cell carcinoma of the skin in children and adults during treatment with voriconazole. J Am Acad Dermatol  2010;62:31-7.

Criscione VD, et al. Natural history and risk of malignant transformation in the Veterans Affairs Topical Tretinoin Chemoprevention Trial. Cancer 2009;115:2523-30.

Jorizzo JL. Current and novel treatment options for actinic keratosis. J Cut Med Surg 2005;8:13-21.

Lehmann P. Methyl aminolaevulinate-photodynamic therapy: a review of clinical trials in the treatment of actinic keratoses and nonmelanoma skin cancer. Br J Dermatol 2007;156:793-801.

Ulrich C, et al. Prevention of non-melanoma skin cancer in organ transplant patients by regular use of a sunscreen: a 24 months, prospective, case-control study. Br J Dermatol 2009;161(Suppl. 3):78-84.


Disclaimer: The material above has been adapted from Therapeutic Strategies prepared by It has not been reviewed by the DermQuest Editorial Board for its accuracy or reliability. Reference to any products, service, or other information does not constitute or imply endorsement, sponsorship, or recommendation by members of the Editorial Board.