Health Insights · Dermatology
Cellulitis and skin infections: recognising and treating them
Cellulitis is a bacterial infection of the skin and the tissue beneath it. Bacteria get in through a break in the skin — a cut, a bite, a scratch, cracked skin between the toes — and spread through the local area. It responds well to antibiotics, rest and elevation, but it needs all three.
Go to an emergency department or call 999 if
- the redness is spreading quickly, or has spread well beyond the line you marked;
- the pain is severe and out of proportion to how the skin looks, or is worsening rapidly;
- the skin blisters, turns dark, purple or black, or areas start to break down;
- you feel increasingly unwell — shivering, vomiting, confused, drowsy, very fast breathing or heart rate;
- you develop a swelling of the face or around the eye;
- you have swelling of the face, throat or mouth, difficulty breathing, or a red itchy rash after taking your antibiotic — stop the medicine and get help immediately.
Cellulitis can occasionally lead to sepsis or to a rapidly spreading deep infection, which is why these signs matter. In an emergency call 999, or go to the Royal London Hospital Emergency Department, Whitechapel Road, London E1 1FR.
Mark the edge, and write the time on it
Draw a line around the outer edge of the redness with a ballpoint or marker pen, and write the date and time next to it. It is the single most useful thing you can do at home.
It turns a vague impression into a fact: at your next check you can see immediately whether the infection is retreating inside the line, sitting still, or spreading past it. Take a photograph each day as well.
Antibiotics
- You will normally be given a course lasting five to seven days, sometimes longer if the infection is slow to settle.
- Finish the whole course, even once the skin looks better. Stopping early lets the infection return and encourages resistant bacteria.
- Take the doses evenly spaced through the day, and space them out again if you miss one — do not double up to catch up.
- Mild nausea or looser stools are common. If side effects become severe, or you develop diarrhoea that is watery or persistent, contact us rather than simply stopping.
Tell us before you start if you are allergic to penicillin
Many cellulitis antibiotics belong to the penicillin family. If you have ever had a reaction to penicillin or any other antibiotic — even years ago, and even if it was only a rash — say so before taking the first dose. There are effective alternatives.
Rest and elevation
This part is genuinely as important as the antibiotics and is the part most often skipped. Swelling slows healing and helps the infection spread.
- A leg: lie down with the leg raised on pillows so the foot is above the level of your heart. Not just up on a footstool — properly above heart level, as much of the day as you can manage in the first few days.
- An arm: rest it on pillows across your chest, or use a sling for short periods, keeping the hand higher than the elbow.
- Keep moving the joints gently while resting the limb, and get up and walk about periodically. Complete immobility raises the risk of a blood clot.
- Drink plenty of fluids.
What normal progress looks like
Cellulitis often looks slightly worse for the first day or two after starting antibiotics before it starts to improve. That is expected and is not a sign the treatment has failed. What we look for by 48 hours is that you feel less unwell, the pain is easing, and the redness is no longer advancing past your mark.
The redness may take a week or two to fade completely, and can leave the skin looking dry, flaky or discoloured for some weeks after the infection has gone. Some swelling can persist for longer still.
Antibiotics and the contraceptive pill
Older leaflets advise extra contraceptive precautions while taking antibiotics. That advice has changed. Ordinary antibiotics such as penicillins do not reduce the effectiveness of the pill, the patch, the ring or any other hormonal contraception, and no additional precautions are needed. A small number of specific medicines do interact — if you are unsure which you have been given, ask us or your pharmacist rather than assuming.
Stopping it coming back
Cellulitis has a habit of recurring in the same limb. Reducing the chance means closing the doors the bacteria came through:
- Treat athlete's foot. Cracked, itchy skin between the toes is one of the commonest entry points for cellulitis of the leg, and is easily treated with a cream from the pharmacy.
- Moisturise dry or eczema-prone skin daily so it does not crack.
- Clean and cover any cut, scratch, bite or graze promptly.
- Manage swelling. If you have long-term swelling of a leg, compression stockings and elevation reduce the risk — ask us about this once the infection has cleared.
- If you have diabetes, check your feet daily and keep your blood glucose well controlled.
Come back for review as arranged, usually at 48 hours, or sooner if the redness passes your mark. We can reassess the skin, take swabs or bloods if needed, change the antibiotic, and arrange intravenous treatment or admission if the infection is not responding. Call 020 7916 0029 — we are open 7 days a week.
Same-day private assessment for cellulitis in East London
Cellulitis is a spreading bacterial skin infection that usually needs antibiotics, and getting seen promptly prevents it worsening. A same-day private GP in East London can confirm the diagnosis, mark the edge to track its spread, start a private prescription, and advise when hospital treatment is required. For anything acute, our urgent care service runs alongside the GP clinic, and where a skin lesion needs a specialist view our private dermatology clinic in London can assess it. Skin infections such as cellulitis are assessed at our private hospital in Whitechapel, East London, close to Canary Wharf, Wapping and the City.
Cellulitis: getting a spreading skin infection treated fast
Can cellulitis be treated same-day privately?
Yes — we offer same-day private GP and urgent care assessment, with antibiotics started where appropriate and clear advice on monitoring.
When is cellulitis an emergency?
Rapidly spreading redness, high fever, feeling very unwell, blistering, or confusion can signal severe infection or sepsis and need urgent care.
How is cellulitis different from other rashes?
Cellulitis is usually warm, tender, spreading and one-sided; a doctor can distinguish it from eczema, a reaction, or a clot.
Do I need a referral?
No — you can be seen directly by our GP or urgent care team, who will refer to dermatology or hospital only if needed.
Where can I get cellulitis treated near me in East London?
A same-day private GP or our urgent care service at Whitechapel, near Canary Wharf and the City, can assess cellulitis and start antibiotics the same day.
When does cellulitis need hospital treatment?
Spreading redness with high fever, feeling very unwell, or cellulitis near the eye needs urgent assessment; we can see you the same day and refer for intravenous antibiotics if required.
Seen today, not next week
Same-day appointments most days, 7 days a week, 9am–7pm, on Whitechapel Road.