Acute lip swelling may be caused by Allergic reactions (eg, to foods, drugs, lipstick, airborne irritants, nickel) Environmental factors (eg, cold and dry weather, sunburn) Hereditary angioedema Nonallergic drug causes (eg, angiotensin-converting enzyme [ACE] inhibitors, calcium channel blockers, certain fibrinolytic drugs) Chronic lip swelling may occur with Acromegaly (often with coarsened facial features and / or enlarged tongue) Hypothyroidism (often with facial puffiness and / or enlarged tongue) Rare causes of chronic lip swelling include ongoing exposure to an unsuspected allergen, cheilitis granulomatosa, and Crohn disease.