Swollen lip with pus: what to know

Pus is thick drainage made of inflammatory cells, fluid, and debris. On the lip, it may come from an infected cut, blocked gland, bitten area, pimple-like lesion, cold-sore complication, or a dental or gum infection that has tracked toward the lip. A tender, warm, red area supports local inflammation.

Allergic swelling generally does not produce pus. Angioedema can cause deep lip swelling, but drainage suggests that a separate skin, mouth, or tooth problem also needs consideration. Do not assume the source from appearance alone.

Wash your hands before and after gently cleaning the area with clean water. Cover external drainage with clean gauze, change it when wet, and avoid sharing towels, cups, lip products, or utensils. Keep food and drink away from an open wound when possible, and choose soft foods if chewing hurts.

Do not lance, squeeze, or scrub the swelling. Do not apply household antiseptics or use someone else’s antibiotics. A clinician or dentist may need to examine the lesion, mouth, teeth, and nearby skin before choosing treatment.

Arrange same-day medical or dental care for pus with increasing swelling, warmth, pain, fever, bad taste, toothache, facial redness, or difficulty opening the mouth. Infection near the mouth can extend into nearby tissues.

Seek emergency help immediately for tongue or throat swelling, breathing or swallowing difficulty, confusion, faintness, or rapidly worsening facial swelling. These symptoms need urgent attention regardless of the amount of drainage.

Could the drainage start in the skin, lip, gum, or tooth? Does the area need a swab, drainage procedure, or prescription treatment? How should I dress and clean it, and which changes should bring me back urgently?