What should you know about cat scratch cellulitis?

A scratch can break the skin and allow bacteria to enter. Cellulitis may cause expanding redness, warmth, swelling, tenderness, and pain around the injury; the border can become difficult to distinguish as it spreads. Fever or swollen glands may occur. A scratch can also cause other infections, so a clinician considers the wound, timing, vaccination history, and your general health rather than diagnosing from redness alone.

Rinse the scratch promptly with running water and soap, remove visible dirt without digging into the wound, and cover it with a clean dressing. Marking the edge of redness can help show whether it is expanding. Arrange same-day medical advice when redness, warmth, swelling, or pain is increasing. Prescribed antibiotics should be taken exactly as directed; do not use someone else's medicine or delay because the wound looks small.

Seek urgent care for rapidly spreading redness, severe pain, fever, confusion, faintness, vomiting, red streaks, numbness, reduced movement, or swelling near the eye or a joint. People with diabetes, poor circulation, or reduced immunity should seek advice early. Serious infection can progress to sepsis, so feeling suddenly very unwell is an emergency.

Ask whether the wound needs cleaning or testing, which antibiotic is suitable, whether tetanus protection is current, how to monitor the border, and which symptoms should send you directly to emergency care.