Cellulitis after a sting: what to know

A sting can cause a local reaction with itch, a raised area, or tenderness. Cellulitis develops when bacteria enter through damaged skin, often after scratching. It tends to produce skin that becomes progressively warmer, more painful, red, or swollen, with the affected area extending beyond the original sting. The two reactions can look similar early on, so a clinician may need to examine the skin and ask how it has changed. See [Cellulitis](/conditions/cellulitis/), [Skin Redness](/symptoms/skin-redness/), and [Skin Swelling](/symptoms/skin-swelling/).

Clean the site gently with soap and water and keep fingernails away from it. If a visible stinger remains, have it removed carefully rather than digging into the skin. Use a clean covering if scratching has opened the area. A cool compress can ease local discomfort. Do not puncture a blister or swollen pocket, and do not use leftover antibiotics. If cellulitis is diagnosed, follow the prescribed treatment and monitor the border for outward movement.

Get same-day advice when redness, warmth, tenderness, or swelling is spreading, or when drainage appears. Seek emergency care for trouble breathing, swelling of the lips or tongue, widespread hives, faintness, or sudden weakness after the sting because these can indicate a severe allergic reaction. Also seek urgent help for [Fever](/symptoms/fever/), confusion, rapid breathing, or feeling very unwell, which can occur with [Sepsis](/conditions/sepsis/). [Type 2 Diabetes](/conditions/type-2-diabetes/) warrants earlier medical advice for a skin wound.

Ask whether the changes fit a local sting reaction, cellulitis, or an abscess; whether the site needs drainage; and how to prevent scratching while it heals. Describe the insect if known, the time of the sting, the speed of change, and any [Painful Skin](/symptoms/skin-pain/).