Cellulitis: symptoms, causes, treatment and which doctor to see
What cellulitis is, how a skin infection spreads under the skin, who is at risk, how antibiotics treat it, and the warning signs that need urgent care.
What cellulitis is
Cellulitis is a bacterial infection of the deeper layers of the skin and the fat just beneath it. It happens when bacteria that normally live harmlessly on the skin get in through a break — a cut, scratch, insect bite, crack between the toes, burn, surgical wound or an area of eczema — and start to multiply. The most common causes are streptococcal (strep) and staphylococcal (staph) bacteria.
It most often affects the lower leg, usually on one side, but it can occur anywhere, including the arms, face and around the eye. With prompt antibiotic treatment most people recover well. Left untreated, the infection can spread into the bloodstream or deeper tissues and become dangerous, which is why a red, hot, spreading patch of skin should be seen by a doctor rather than watched for days.
Symptoms
Cellulitis usually develops over a day or two. Typical signs in the affected area are:
- Red skin that spreads outwards, often with a blurred edge; on darker skin the redness can be harder to see and the area may look darker, purple or simply shiny
- Swelling, and skin that may look tight or dimpled like orange peel
- Warmth — the area feels hotter than the skin around it
- Pain and tenderness when touched
- Sometimes blisters, small red spots or a weeping surface
Many people also feel generally unwell, with fever, chills, tiredness or aching, sometimes before the skin changes appear. Swollen, tender lymph glands in the groin or armpit and a red streak running up the limb are signs that the infection is spreading along the lymph channels.
A red, swollen, painful calf can also be a blood clot (deep vein thrombosis), and a tender lump that fills with pus is more likely an abscess. Both need a doctor, and the treatment is different, so it is worth getting the diagnosis right.
Causes and risk factors
Anyone can get cellulitis, but it is more likely if you have:
- Cracked or peeling skin between the toes from athlete's foot or other fungal infection — a common, easily missed entry point, especially in hot, humid weather and when feet stay wet in the monsoon
- Cuts, insect or animal bites, wounds from walking barefoot, or a recent operation
- Eczema, psoriasis or other conditions that break the skin
- Diabetes, which slows healing and makes foot infections more serious — see diabetic foot
- Long-standing swelling of the legs or arms (lymphoedema), including after lymph node surgery, or from varicose veins and poor circulation
- Excess body weight, a weakened immune system, or a previous episode of cellulitis
Cellulitis itself is not usually passed from person to person by normal contact. Even so, wash your hands after touching the area and keep any open wound covered.
How it is diagnosed
Cellulitis is usually diagnosed by a physical examination — the doctor looks at the skin, feels for warmth and tenderness, checks for a wound or crack where bacteria could have entered, and asks about fever, diabetes and previous episodes. Tests are not always needed for mild cases, but your doctor may use:
- Blood tests to look for signs of infection and inflammation, check blood sugar, and check kidney function before some medicines
- A swab culture from an open wound, blister or pus to identify the bacteria and which antibiotics they respond to
- An ultrasound to look for a collection of pus (abscess) that needs draining, or a Doppler scan of the leg veins if a blood clot is possible
- Blood cultures and further scans if you are very unwell or the infection is spreading quickly
Many doctors draw a line around the edge of the redness with a pen, so that you and they can see over the next day or two whether it is spreading or shrinking.
Treatment
Antibiotics are the main treatment. For mild to moderate cellulitis these are usually tablets taken at home. Your doctor will choose the medicine based on the likely bacteria, any allergies, and local patterns of resistance. Take the full course exactly as prescribed, even once the skin looks better, and do not use leftover or borrowed antibiotics.
If the infection is severe, spreading fast, affecting the face or eye, or you are unwell with high fever, vomiting or diabetes that is hard to control, you may need admission for intravenous antibiotics given through a drip. An abscess may need to be opened and drained.
Helping it heal
- Elevation — keep an affected leg raised above the level of your hip when resting, to reduce swelling and pain
- Rest, drink enough fluids, and use simple painkillers your doctor or pharmacist says are suitable
- Treating skin breaks and the cause — for example antifungal treatment for athlete's foot, or care of an ulcer or wound
- Do not apply turmeric pastes, oils or home remedies to broken skin; keep it clean and covered as advised
The redness may look slightly worse in the first day of antibiotics before it settles. If it keeps spreading after a couple of days of treatment, or you feel worse, go back to your doctor promptly.
Preventing it coming back
Cellulitis can recur, especially in a leg that stays swollen. You can lower the chance by:
- Checking your feet daily, particularly if you have diabetes, and drying well between the toes
- Treating athlete's foot and cracked heels early, and moisturising dry skin
- Cleaning cuts and bites promptly and wearing footwear outdoors
- Controlling blood sugar and body weight, and managing leg swelling with the support your doctor suggests
- Asking your doctor about longer-term prevention if you have had several episodes
When it is an emergency
Call 112 or 108, or go to the nearest emergency department, if:
- The redness is spreading quickly, over hours rather than days
- Pain is severe and seems out of proportion to how the skin looks, or the skin turns dusky, purple, black or numb — signs of a rare but serious deep infection
- Cellulitis is around the eye, with swelling of the eyelids, eye pain, or difficulty moving the eye or seeing
- You have high fever, shivering, fast breathing, a racing heart, confusion, or feel faint — these can be signs of sepsis
Which doctor to see
Most cellulitis is diagnosed and treated by a general physician or an internal medicine specialist. A dermatologist can help when it keeps coming back or the diagnosis is unclear, since several skin conditions can look similar. An infectious diseases specialist may be involved for severe, unusual or resistant infections, and a surgeon if an abscess or deep infection needs draining.
You can find general physicians in Bengaluru or dermatologists in Bengaluru on The Doctor Index, each with a registration you can check.
Common questions
Questions people ask
- Is cellulitis contagious?
- Cellulitis is not usually spread from one person to another through normal contact. The bacteria come from your own skin or the environment and get in through a break. Still, wash your hands after touching the area and keep wounds covered.
- How long does cellulitis take to heal?
- Most people start to feel better within a few days of starting antibiotics, although swelling and discolouration can take longer to fade. If you are not improving after two or three days of treatment, see your doctor again.
- Can cellulitis be treated without antibiotics?
- No. Cellulitis is a bacterial infection and needs antibiotics prescribed by a doctor. Rest, elevation and keeping the skin clean help, but home remedies alone can allow the infection to spread into the blood or deeper tissues.
- Why does cellulitis keep coming back in my leg?
- Repeat episodes often happen when there is an ongoing entry point or swelling, such as athlete's foot, cracked heels, lymphoedema or poorly controlled diabetes. Treating these causes is key. Your doctor may also discuss preventive antibiotics if episodes are frequent.
This condition is usually assessed by an internal medicine physician. Every profile shows the doctor’s registration and what has been checked.
Internal medicine physicians in Bangalore
A few internal medicine physicians listed on The Doctor Index. They are shown because of their speciality, not a stated interest in Cellulitis; ask the clinic whether the doctor sees it.
All general medicine conditions →
Practical reading
All postsSources
- MedlinePlus, US National Library of Medicine — Cellulitis
- Government of India — Emergency Response Support System (112)
- MedlinePlus, National Library of Medicine — Cellulitis — Public-domain health-topic summary
Cellulitis: symptoms, causes, treatment and which doctor to see is original text by The Doctor Index; the compiled source draft was used for research. Source: MedlinePlus, National Library of Medicine. Orphadata Science: Free access data from Orphanet. © INSERM 1999; July 2026 data, CC BY 4.0. This product uses the Human Phenotype Ontology (hp/releases/2026-09-01). Only sources listed for this article apply. Source material has been selected and arranged; HPO definitions are reproduced without alteration. No source organisation endorses this compilation. Köhler S et al. The Human Phenotype Ontology project: linking molecular biology and disease through phenotype data. Nucleic Acids Research 2014;42(D1):D966–D974. doi:10.1093/nar/gkt1026.
General information, not advice about your situation. Errors can be reported through the corrections process. Reference TDI-C-0455.