Actinic keratosis or solar keratosis, results from the proliferation of atypical epidermal keratinocytes. See a lot of them among older and middle aged sun worshippers and sunscreen agnostics. The approach has been to use liquid nitrogen. But review of guidelines prepared on behalf of the British Association of Dermatologists has opened to other approaches.
The likelihood of progression of an AK to squamos cell carcinoma (SCC) is low. Estimates from a large US cohort revealed a rate of transformation to invasive or insitu SCC of 0.6 percent after one year and 2.6 percent after four years. Even so, 60 percent of SCC arise from AKs. Topical therapies with an A grade (good evidence) included no therapy or emollients for mild AKs and 5-fluorouracil. Those with a B grade (fair evidence) include diclofenac gel and imiquimod. Also, cryosurgery gets A grade; photodynamic therapy gets a B grade.
According to a paper in the Drugs and Therapeutic Bulletin, patients should be referred to a dermatologist if there is diagnostic uncertainty, concern about malignancy, treatment failure, management concerns, or high risk (for example, organ transplant recipient, multiple large lesions, or prior SCC).
There is inadequate evidence to justify treatment of all AKs to prevent malignant transformation must consider all approaches. One liquid nitrogen bottle does not fit all.