RESUMEN
INTRODUCTION: Actinic cheilitis (AC) is part of a spectral disease of keratinocyte carcinomas considered by some authors an early stage of in situ squamous cell carcinoma. Treatment options for AC can be lesion and field-directed therapies. Ingenol mebutate (IM) induces rapid and direct cell death and immune responses being able to destruct dysplastic cells. MATERIALS AND METHODS: This study enrolled patients with AC to receive IM gel 0.015% for self-application on the lower lip for 3 consecutive days. A biopsy was performed before and after treatment for histopathological and immunohistochemical evaluation. Local skin reactions (LSR) were evaluated. The level of significance considered was 5%. RESULTS: Fourteen patients were enrolled. All LSR had a complete resolution for up to 2 weeks. The most common adverse events were burning sensation, angular cheilitis, and pain. There was an improvement of more than 80% in patients' subjective evaluation. There was no statistically significant histopathological response since all patients remained with mild dysplasia. No reduction in the P53 expression was observed in the current study. CONCLUSIONS: Despite being a safe therapeutic method, the absence of histopathological or immunohistochemical response suggests that clinical improvement may not be accompanied by histopathological cure for AC treated with IM.