Cellulitis
Cellulitis is a bacterial infection of deeper skin layers that can spread if untreated.
About cellulitis
Cellulitis is a bacterial infection of deeper skin layers that can spread if untreated.
What can cause it?
Cellulitis occurs when bacteria enter deeper skin through a cut, crack, ulcer, bite, or other skin break.
Swelling, poor circulation, diabetes, athlete's foot, and immune problems increase risk.
What a patient may notice
Symptoms vary from person to person. Possible signs may include:
- Expanding redness, warmth, swelling, or pain
- Tender skin or red streaks
- Fever, chills, or drainage
How clinicians find the cause
Diagnosis is usually clinical. Blood tests, ultrasound, culture, or imaging may be needed when an abscess, blood clot, bone infection, or severe systemic infection is possible.
Treatment and next steps
- 1
Antibiotics are selected according to location, severity, allergies, and risk factors.
- 2
An abscess must be drained; severe or rapidly spreading infection may need IV antibiotics and hospital care.
- 3
Marking the edge of redness can help monitor spread.
Supporting recovery
- Take every antibiotic dose as directed and elevate the affected limb when appropriate.
- Keep wounds clean and do not squeeze infected areas.
What to expect
Cellulitis usually improves with the correct antibiotic, although redness can take time to fade and severe infection may require longer treatment. The area should be reassessed if it continues to spread, new fever develops, or there is no clear improvement after treatment begins. Recurrence is more likely when swelling, diabetes, skin cracks, or fungal foot infection remain untreated.
Possible complications
- Abscess formation or infection spreading into muscle, bone, lymph vessels, or the bloodstream
- Sepsis, shock, tissue death, or other organ infection when severe cellulitis is not controlled
- Repeated cellulitis with lasting swelling or lymphatic damage
When to Contact a Medical Professional
A same-day medical evaluation is recommended, especially when symptoms are severe, worsening, or accompanied by fever, vomiting, weakness, or significant pain.
Call 911 or go to the emergency department for confusion, fainting, rapid spread, severe pain, purple or black skin, or infection near the eye with vision symptoms.Get emergency help for severe trouble breathing, new chest pressure, fainting, seizure, sudden weakness on one side, uncontrolled bleeding, blue or gray lips, or a person who is difficult to wake.
Ways to lower risk
- Treat skin cracks and fungal foot infection, moisturize dry skin, and protect wounds.
- Manage swelling and diabetes with the care team.
Trusted health information
This CHS patient-education page uses original wording and links to MedlinePlus for additional information.