Cellulitis is a bacterial skin infection that makes your skin look red, swollen, and feel hot and tender. It usually happens on your lower legs, but it can appear anywhere on your body. The infected area often has a red patch that spreads quickly, and the skin might look tight, shiny, or pitted like an orange peel. This is not a minor rash — cellulitis is a serious infection that needs medical attention right away.
What Are the First Signs of Cellulitis?
The first sign is usually a red patch of skin that grows larger over hours or days. The skin in that spot feels warm or hot to the touch. Many people describe it as a burning sensation. The area also swells, and the swelling can make the skin feel tight.
You might also notice a small cut, bug bite, or other break in the skin near the red area. That is where the bacteria entered. The red border is often not sharp — it fades into the surrounding skin. Some people get blisters on top of the red area. These blisters can be small or large.
Pain is common. The area hurts when you touch it or move that part of your body. If the infection is on your leg, walking can hurt. If it is on your arm, lifting or using that arm can be painful. The pain level varies, but it is usually more than you would expect from a simple skin injury.
How Can You Tell Cellulitis From Other Skin Conditions?
Cellulitis looks different from eczema or allergic reactions in key ways. Eczema is usually itchy, dry, and comes and goes. Cellulitis is painful, hot, and gets worse over time. Allergic rashes often have raised bumps or hives and appear all over the body. Cellulitis stays in one area and spreads from there.
Venous stasis dermatitis is a common condition that people mistake for cellulitis. It happens when poor circulation in the legs causes redness, swelling, and skin changes. The difference is that stasis dermatitis usually affects both legs equally. Cellulitis is almost always on one side only. Stasis dermatitis also does not cause fever or chills.
If you have redness on both legs with no fever, it is probably not cellulitis. If you have redness on one leg with swelling, heat, and pain, it could be. The CDC reports that cellulitis is one of the most common reasons people visit emergency rooms for skin infections. When in doubt, get checked by a doctor.
What Does Cellulitis Look Like in Darker Skin?
Cellulitis looks different on darker skin tones, and this matters because it is often missed or diagnosed late. On light skin, the redness is obvious. On dark skin, the redness may look more like a dark purple, gray, or ashen color. The skin might not look red at all — it might just look darker than the surrounding skin.
Research published in the Journal of the American Academy of Dermatology found that doctors are more likely to miss cellulitis in Black patients. The classic “redness” sign is less visible. Instead, look for these signs: warmth to the touch, swelling, tight or shiny skin, and pain. If the skin feels hot and looks different in color or texture from the other side, that is a red flag.
Fever and chills are important clues regardless of skin color. If you have a hot, swollen, painful patch of skin and you feel feverish, do not wait. Go to a doctor. Tell them you are worried about cellulitis. Do not assume they will see what you see.
What Systemic Symptoms Accompany Cellulitis?
Cellulitis is not just a skin problem. It is an infection that can spread to your bloodstream. When that happens, you get whole-body symptoms. Fever is the most common — your body temperature goes above 100.4°F. Chills and sweats often come with the fever.
You might feel generally awful. Fatigue, muscle aches, and nausea are common. Some people get a fast heart rate or feel dizzy. These symptoms mean the infection is serious and needs treatment quickly. The American Academy of Family Physicians states that systemic symptoms are a sign that oral antibiotics may not be enough — you might need IV antibiotics in a hospital.
If you have a red, swollen patch of skin and you also have a fever, do not try to treat this at home. Go to urgent care or the emergency room. Do not wait to see if it gets better on its own. It will not.
How Is Cellulitis Treated?
Cellulitis requires antibiotics. This is not optional. The bacteria causing the infection — usually Streptococcus or Staphylococcus — will keep spreading without treatment. Antibiotics stop the infection and prevent it from reaching your bloodstream.
Most people get oral antibiotics for 7 to 14 days. Your doctor will choose an antibiotic based on your medical history and how severe the infection looks. Common choices include cephalexin, dicloxacillin, or clindamycin. You need to take the full course even if the skin starts looking better after a few days. Stopping early can make the infection come back stronger.
For severe cases, you get IV antibiotics in a hospital. Signs that you need IV treatment include high fever, rapid spreading of the red area, severe pain, or other medical conditions like diabetes or a weak immune system. Some people go home with a PICC line and give themselves IV antibiotics for a week or more.
Supportive care matters too. Elevate the infected limb above your heart to reduce swelling. Rest the area. Apply a cool, damp cloth for comfort if the doctor says it is okay. Do not use heat — heat can make swelling worse. Do not try to drain any blisters yourself. That can introduce more bacteria and make things worse.
What Are the Risk Factors for Cellulitis?
Anything that breaks your skin increases your risk. Cuts, scrapes, surgical wounds, bug bites, and athlete’s foot cracks between the toes are all common entry points for bacteria. People with eczema or dry, cracked skin are also at higher risk.
Certain medical conditions raise your risk significantly. Diabetes makes it harder for your body to fight infections. Poor circulation in your legs — called venous insufficiency — means your body cannot deliver immune cells to the infection site as quickly. Lymphedema, which is swelling from damaged lymph vessels, also increases risk. People who have had cellulitis before are more likely to get it again.
Obesity is a risk factor too. Research in the journal Clinical Infectious Diseases found that obesity triples the risk of recurrent cellulitis. The reasons are not fully understood, but excess body fat may affect immune function and circulation in the skin.
When Should You See a Doctor for Cellulitis?
See a doctor the same day you notice a red, swollen, hot patch of skin that is growing. Do not wait 24 hours to see if it improves. Cellulitis can spread fast. A small patch in the morning can cover your whole lower leg by evening.
Go to the emergency room immediately if you have any of these: a fever over 100.4°F, chills, rapid heart rate, confusion, or the red area is growing very fast — spreading past a drawn line within hours. Also go to the ER if the infected area is on your face or near your eyes. Cellulitis near the eyes can spread to the brain and is a medical emergency.
If you have diabetes, a weak immune system from chemotherapy or medications, or you have had your spleen removed, do not wait. Go to the ER at the first sign. These conditions make cellulitis much more dangerous because your body cannot fight the infection normally.
Common Misconceptions About Cellulitis
One common myth is that cellulitis is contagious. It is not. You cannot catch cellulitis from someone else. The bacteria that cause it live on your own skin normally. They only cause infection when they get through a break in your skin. You do not need to isolate or clean surfaces differently.
Another myth is that spider bites cause cellulitis. This is widely claimed, but strong evidence is limited. Most people who think a spider bite caused their cellulitis never actually saw a spider. The red, swollen spot they thought was a bite was probably the infection itself. True spider bites are rare and usually cause a different pattern of injury.
A third myth is that you can treat cellulitis with home remedies. You cannot. Tea tree oil, apple cider vinegar, turmeric paste — none of these kill the bacteria deep in your skin and tissue. These remedies can actually delay proper treatment and let the infection get worse. Antibiotics are the only proven treatment. The CDC, the American Academy of Dermatology, and every major medical organization agree on this point.
| Condition | Key Features | What It Is Not |
|---|---|---|
| Cellulitis | Red, hot, swollen, painful, one-sided, growing | Not itchy, not on both sides |
| Eczema | Itchy, dry, flaky, comes and goes | Not hot, not painful, not growing fast |
| Venous stasis dermatitis | Both legs, brownish discoloration, mild swelling | No fever, no rapid spread |
| Allergic contact dermatitis | Itchy, raised bumps, appears after exposure to something | No fever, not hot to touch |
| Insect bite reaction | Small raised bump, itchy, localized | Not spreading, not hot |
- Cellulitis always needs antibiotics — no exceptions
- Draw a line around the red area with a pen to track spread
- If the redness crosses the line within hours, go to the ER
- Keep the area clean and dry
- Do not scratch or pick at the skin
- Finish all antibiotics even if you feel better
Frequently Asked Questions
Can cellulitis go away on its own?
No. Cellulitis will not go away without antibiotics. It will spread and can become life-threatening if untreated.
How fast does cellulitis spread?
Cellulitis can spread inches per hour in severe cases. That is why you need treatment immediately.
Is cellulitis the same as staph infection?
No. Staph is one type of bacteria that can cause cellulitis, but cellulitis is the infection itself, not the bacteria.
Can you put ice on cellulitis?
A cool, damp cloth is okay for comfort, but do not use ice directly. Ice can damage skin that is already inflamed.
