Cellulitis is a common bacterial skin infection that affects the deeper layers of skin. While it's usually treatable with antibiotics, it can become serious if not addressed promptly. Recognizing the signs early is crucial for getting proper treatment.
What Is Cellulitis?
Cellulitis occurs when bacteria (usually Streptococcus or Staphylococcus) enter through a break in the skin and infect the deeper layers of skin and underlying tissue. It's not contagious to others.
Signs and Symptoms
- Redness: Area of red skin that spreads and expands
- Swelling: Affected area becomes puffy and swollen
- Warmth: Skin feels hot to touch
- Pain: Tenderness and pain in affected area
- Skin tightness: Stretched, shiny appearance
- Red streaks: May radiate from infected area
- Fever and chills: In more severe cases
- Blisters: May develop in some cases
- Dimpled skin: "Orange peel" texture
Common Locations
- Lower legs: Most common site
- Feet: Especially in people with diabetes or athlete's foot
- Arms and hands: Often after injury
- Face: Can be particularly serious
- Around wounds: Surgical sites, cuts, insect bites
How Bacteria Enter the Skin
- Cuts, scrapes, or puncture wounds
- Surgical incisions
- Insect or animal bites
- Athlete's foot or fungal infections (creates cracks)
- Dry, cracked skin (especially on heels)
- Eczema or dermatitis
- IV drug use
- Tattoos or piercings
Risk Factors
- Weakened immune system: HIV, chemotherapy, immunosuppressants
- Diabetes: Poor circulation and sensation in feet
- Obesity: Increased risk
- Lymphedema: Chronic swelling
- Chronic venous insufficiency: Poor leg circulation
- Previous cellulitis: Increases risk of recurrence
- Skin conditions: Eczema, athlete's foot
Emergency Warning Signs
Seek emergency care immediately if you have:
- High fever (above 38.5°C/101.3°F) with skin infection
- Rapidly spreading redness (mark edges with pen to track)
- Severe pain out of proportion to appearance
- Numbness in affected area
- Black or purple discoloration
- Large blisters or skin breakdown
- Confusion or altered mental state
- Signs of sepsis: rapid heartbeat, rapid breathing, feeling very unwell
These may indicate necrotizing fasciitis or sepsis—life-threatening emergencies.
Cellulitis vs Other Conditions
| Condition | Key Difference |
|---|---|
| DVT (blood clot) | Usually one leg, less red, more deep pain |
| Contact dermatitis | Itchy, clearly defined borders, often bilateral |
| Gout | Usually affects joints, especially big toe |
| Venous stasis | Both legs, brownish discoloration, chronic |
| Abscess | Localized, fluctuant (squishy), may need drainage |
Treatment
Antibiotics
- Oral antibiotics: For mild to moderate cases (7-14 days typically)
- IV antibiotics: For severe cases or if oral treatment fails
- Common antibiotics: Flucloxacillin, cephalexin, clindamycin
- Complete the course: Even if you feel better
Supportive Care
- Elevate affected limb: Reduces swelling
- Rest: Avoid excessive activity
- Pain relief: Paracetamol or ibuprofen
- Cool compresses: May provide comfort
- Mark the edges: Track if redness is spreading or shrinking
Prevention
- Clean wounds promptly: Wash with soap and water
- Cover cuts and scrapes: With clean bandages
- Moisturize dry skin: Prevents cracking
- Treat athlete's foot: Fungal infections create entry points
- Protect skin: Wear gloves when gardening, long sleeves in brush
- Manage underlying conditions: Diabetes, eczema, lymphedema
- Check feet daily: Especially if diabetic
- Compression stockings: For chronic swelling
When to See a Doctor
- Red, warm, painful, swelling skin
- Redness that is spreading
- Any skin infection with fever
- Previous cellulitis and symptoms returning
- Wound that isn't healing normally
- Weakened immune system with any skin infection