Infected insect bite cellulitis: what to know

A bite can create a small opening in the skin. Scratching, blistering or rubbing may enlarge that opening, allowing bacteria to reach deeper tissue. Cellulitis often produces a warm, painful, swollen red area that expands beyond the original bite. The surface may not show pus. This is different from a short-lived itchy reaction, which commonly stays close to the bite and gradually eases.

Arrange prompt medical assessment when redness is spreading or the skin is increasingly hot, swollen or painful. Keep the area clean, avoid scratching, and elevate an affected arm or leg when comfortable. Do not massage the red area or apply irritating home remedies. A clinician may mark the edge of redness to track change and decide whether prescription treatment is needed. Mention diabetes, immune problems or a recent wound when you are assessed.

Seek urgent help for fever, chills, rapidly expanding redness, red streaks, severe pain, confusion, faintness or marked weakness. Emergency assessment is especially important when swelling affects the face or eye, or when you feel suddenly very unwell. Untreated cellulitis can spread beyond the skin and needs timely medical attention.

Does this look like cellulitis or an insect-bite reaction? How should I monitor the edge of redness? Which symptoms mean I should return urgently? Could another skin problem, such as athlete's foot, be allowing bacteria to enter?