Actinic Keratoses

Actinic keratoses (AK) are premalignant skin lesions occurring in sun-damaged skin. They appear clinically as erythematous papules with a rough scaly surface (18). Early lesions may be felt more than seen. Most commonly, AK affect the exposed skin of the face and upper extremities. The cheeks, forehead, and dorsum of hands are frequent locations (Fig. 8). The lower lip (actinic cheilitis) and, in balding men, the scalp are also involved. Lesions are multiple and develop gradually over the years. Most tend to become thicker (hypertrophic AK). The rate of malignant transformation for each individual AK is approximately 5%, but in patients with multiple lesions the risk is over 20%. On histopathological examination the most characteristic findings are variable degrees of focal epidermal displa-sia with overlying parakeratosis and crowding of basal cells. The dermis shows solar elastosis.

Cryotherapy with liquid nitrogen may be the treatment of choice. It is effective, |

quick, inexpensive, and widely available (19). Two freezing cycles of 10 s each are ยป

usually sufficient for each lesion, although, hypertrophic AKs require longer cycles. c

Topical 5-fluorouracil (5-FU) (an antimetabolite that blocks the incorporation d of thymidine into DNA) is also effective. The usual regimen involves twice-daily applications and a topical steroid is prescribed to decrease the inflammatory reaction, which in some patients is quite severe. Another option involves application of topical 5-FU in the morning and night in combination with topical tretinoin (Retin A) at midday for 4 weeks. @

Figure 8 Actinic keratoses on the forehead of an albino female patient. The lesions are red with a rough scaly surface.

Medium-depth chemical peel is indicated for multiple lesions and extensive solar damage. We prefer glycolic acid 70% for 2min followed by trichloroacetic acid (TCA) 30% until mild frosting; or Jessner's solution (resorcinol 14 g, salicylic acid 14g, lactic acid 14g) followed by TCA 35%. Treatment is done under local anesthesia, peeling occurs at 4 days, and complete recovery is usually seen at 7 days.

Dermabrasion and ultrapulse CO2 laser therapy yield similar results to chemical peel. The latter is the treatment of choice for actinic cheilitis.

Curettage and electrodesiccation are the preferred modalities for hypertrophic AKs because these are the only modalities that provide a histological specimen to allow one to rule out squamous cell carcinoma.

How To Reduce Acne Scarring

How To Reduce Acne Scarring

Acne is a name that is famous in its own right, but for all of the wrong reasons. Most teenagers know, and dread, the very word, as it so prevalently wrecks havoc on their faces throughout their adolescent years.

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