Abstract Angioneurotic edema is a life-threatening condition that manifests as a vascular reaction affecting the skin and mucous membrane. It commonly occurs in the head-and-neck area and can be triggered by allergens, medications, or hereditary factors. This report presents the case of a 30-year-old male who presented acute lower lip swelling following breakfast. His diagnostic workup included normal C1-esterase inhibitor levels, complete blood count, and inflammatory markers. The patient was successfully managed with oral antihistamines, leading to symptom resolution within 3 days. This case highlights the importance of prompt identification and management of acute angioneurotic edema.