Earliest stage treatment of actinic keratosis with imiquimod 3.75% cream: Two case reports—Perspective for non melanoma skin cancer prevention

Imiquimod 3.75% cream is licensed for the treatment of actinic keratosis (AK). Two case reports on the treatment of facial UV-exposed skin shall open the discussion if subclinical AKs can be detected by the use of imiquimod cream in UV-exposed areas even if no lesions can be found clinically. A 87-year old female showing small scaly AK lesions on her right cheek was treated with imiquimod 3.75% cream. A 59-year old female without obvious clinical signs of UV-damage on the face experimentally applied imiquimod 3.75% cream twice daily on the entire face for 2 weeks. In the 87-year old, inflammatory reaction developed from day 3 onward and showed field cancerization, the lesions healed without scarring. In the 59-year old at the end of the treatment phase, distinct signs of inflammation appeared, then taking 2 weeks for healing without sequalae. These results open the discussion if the use of imiquimod 3.75% cream could be recommended preventively in UV-exposed skin areas to obviate a later development of AKs/squamous cell carcinoma/nonmelanoma skin cancer.