LAUSR

Background Ingenol mebutate (IM), a novel agent for field therapy of actinic keratosis (AK), has a drawback of inducing local skin reactions (LSRs), which may cause discomfort in patients. To reduce the LSRs, we tried the application of IM in low amounts. Objective The purpose of this study was to review Korean patients with AK being treated with IM and evaluate the LSRs and therapeutic outcomes of low amounts of IM. Methods We retrospectively reviewed 47 patients with AK on the face. A total of 20 and 27 patients were treated by applying recommended amount of 18.8 mg/cm2 and the lower amount of 10 mg/cm2, respectively. Results The mean composite LSR score for the low amount group (LAG; 12.18±3.29) was significantly lower than that for the recommended amount group (RAG; 15.45±2.70) (P<0.01, independent sample t-test). The 2-month clearance rate calculated by the number of AKs before and after treatment in each patient was significantly higher for RAG (88.16%), compared with 75.56% for LAG (P<0.001). Conclusion Low amount of IM for the treatment of facial AK significantly reduced LSRs in Korean patients. Minimizing LSRs may allow for a secondary targeting treatment of IM for the residual lesions, depending on initial treatment outcomes.