Battle sign is a clinical feature characterized by bruising over mastoid region behind the ear. It is mostly seen in trauma and assault patients. The condition is attributed to fracture of the base of the skull. Reference: https://www.ncbi.nlm.nih.gov/books/NBK537104/#:~:text=Battle%20Sign%20(also%20called%20Battle Image via: https://25hournews.com/news/the-battle-sign-that-appears-behind-the-ears-3000