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Dr. Chrysoula I. Liakou MD, PhD
- Treated online: Yes, for early, limited cellulitis in an adult who feels well; fever, fast spread, redness on the face or around an eye, or red streaks towards the groin or armpit need in-person care.
- What it is: a bacterial infection of the deeper skin and the tissue beneath it, usually by streptococci or Staphylococcus aureus entering through a crack, cut, ulcer or athlete's foot; 9 in 10 cases are on one lower leg.
- Pen-line test: draw round the edge of the redness and note the time; antibiotics are winning if the redness stays inside the line, and clear spread beyond it within 24 hours means escalate.
- One leg or two: cellulitis is almost always one-sided; red, itchy, scaly skin on both lower legs is usually varicose eczema, which needs moisturiser and steroid cream, not antibiotics.
- How long: pain and heat ease within 24 to 48 hours of antibiotics, courses run 5 to 7 days, and the colour fades over 1 to 2 weeks or more, often with flaking; about 1 in 3 people have a repeat episode within 3 years.
- Emergency: call 112 for cellulitis with shaking chills, confusion, a racing heart, fast breathing, pain far worse than the skin looks, or skin that is darkening, blistering or going numb.
Cellulitis can escalate quickly, so read this first. Go to in-person care today, or call 112, if the redness involves your face or the skin around an eye, if red streaks run from the area toward your groin or armpit, if you have fever, shaking chills, confusion, vomiting or a racing heart, or if the skin is rapidly darkening, blistering or turning numb. Book online for a limited area of redness in someone who otherwise feels well.
Can an online doctor treat cellulitis?
Yes, for early, limited cellulitis in an otherwise well adult. The diagnosis is largely visual, so a doctor can assess the hot, red, swollen area from photos and video and prescribe oral antibiotics when the picture supports it. Cellulitis with fever, fast spread, facial involvement or red streaks needs in-person care instead.
Speed is the whole point. Cellulitis treated within its first hours usually stays a one-week nuisance on tablets; cellulitis left to spread can mean intravenous antibiotics and a hospital bed.[5] Mobi Doctor is built for that window: a video assessment, treatment when the doctor judges it safe, and an unambiguous instruction to go in person when the picture demands it. You can see a doctor over video, usually within 15 minutes.
Listen: Cellulitis Treatment Online
The audio version of this topic from the Mobi Doctor podcast. Open the episode.
How an online consultation helps with cellulitis
- Timing matters: video appointments daily 7am–11pm CET mean a doctor can assess the redness early, not after a two-day wait.
- A diagnosis photos can carry: warmth, swelling, tenderness and an advancing border tell a clear story on good images plus a video conversation.
- The pen-line trick, built into your plan: the doctor shows you how to mark the edge of the redness and use it as an objective tripwire for escalation.
- A clear escalation plan: you finish the call knowing exactly which changes mean "go in tonight" and when your 48-hour review lands.
📷 Photograph the whole limb from two angles in daylight, then take a sharp close-up of the border where red meets normal skin. Before the consultation, draw around the edge of the redness with a ballpoint pen and write the time beside the line: photos repeated a few hours apart then show at a glance whether the infection is shrinking, holding or advancing past the line.
What the doctor checks in an online cellulitis consultation
The assessment is structured around the findings that decide between tablets at home and in-person care. In a cellulitis consultation, the doctor will typically assess:
- How fast it is moving: redness that grew over days behaves differently from redness that doubled over an afternoon; your dated photos and pen line make this objective.
- One leg or both: true cellulitis is almost always one-sided. Red, itchy, scaly skin on both lower legs is usually varicose eczema, a circulation-related rash that antibiotics do not help.[1]
- The entry point: athlete's foot between the toes, cuts, insect bites, ulcers, dry cracked skin or a recent wound; finding and treating the door the bacteria used prevents the next episode.[1]
- Systemic signs: your temperature, chills, feeling unwell, heart rate and general state, which are the main triggers for in-person care.[2]
- High-risk territory: face and eye area, hands, genitals, or skin over joints and implants, where thresholds are lower.
- Your risk profile: diabetes, lymphoedema or chronic leg swelling, previous cellulitis, immunosuppression, obesity and vein problems, all of which change both treatment and follow-up.[1]
- Allergy and medicines: penicillin allergy and interactions steer the antibiotic choice.
- The story behind unusual exposures: animal or human bites, and wounds sustained in fresh or salt water, involve different bacteria and are redirected to in-person care.
What does cellulitis look like?
Cellulitis is an expanding area of red, hot, swollen, tender skin, most often on one lower leg, with edges that fade gradually into normal skin. On darker skin the redness can be subtle: look for warmth, shine, tightness and swelling instead. Blisters, and fever or feeling unwell, appear as it progresses.[3]
Cellulitis or something else?
Several conditions imitate it, and the imitators do not need antibiotics. Varicose (stasis) eczema affects both legs, itches more than it hurts, and simmers for months, where cellulitis is one-sided, tender and new; treating it lives on the eczema page. An insect bite reaction swells within minutes to hours of the bite and itches, in a person who feels well. A deep vein thrombosis swells the calf with less surface redness and warmth; it needs same-day in-person assessment of its own. Gout inflames a joint, classically the big toe. Shingles forms a painful, blistering band on one side. The video consultation is designed to separate these, because a week of antibiotics for the wrong diagnosis helps nobody.[3]
Erysipelas, the sharper cousin
Erysipelas is a closely related infection of the more superficial skin layers: brighter red, raised, with a sharply defined border, often on the face or lower leg, and frequently with sudden fever. It is managed with the same urgency and largely the same antibiotics as cellulitis, and everything on this page about escalation applies to it equally.[3]
How quickly do antibiotics work for cellulitis?
Most people feel the tide turn within 24–48 hours of the first dose: pain eases, fever settles and the redness stops advancing. The colour itself can take one to two weeks or more to fade fully, and the skin often flakes as it heals. Courses are typically 5–7 days, extended when improvement is slow.[2]
Two honest details stop unnecessary panic and unnecessary delay alike. First, redness can creep slightly outward in the first day even when antibiotics are working, which is exactly why the pen line and the 48-hour review exist: modest blurring at the margin with less pain is acceptable, clear expansion past the line with fever is not. Second, finishing the course matters, and so does not hoarding leftovers: antibiotic stewardship means the right drug, at the right dose, for the right number of days, and cellulitis is a condition where that discipline genuinely protects future patients as well as you.[2]
Why do I keep getting cellulitis in the same leg?
Each episode of cellulitis damages the fine lymphatic channels that drain the leg, the swelling that follows makes the next infection easier, and the cycle repeats. Breaking it means closing the doors bacteria use: treat athlete's foot properly (the ringworm and fungal infection page covers it), moisturise dry, cracked skin daily, manage leg swelling, and care for wounds early.[1]
After the infection has fully cleared, compression stockings help control chronic swelling, and weight reduction lowers recurrence risk. For people with repeated episodes, guidelines support discussing long-term, low-dose preventive antibiotics with the clinician who manages you; that is a specialist-flavoured decision made in person, with the trade-offs on the table.[1] An online review is a good place to assemble this prevention plan once the emergency is over.
Which cellulitis treatment might the doctor recommend?
Treatment follows severity and territory. This is the framework the doctors use, aligned with the cited guidance:[2]
Swipe sideways to compare →
| Presentation | Likely first step | Suitable for online care? | When referral or in-person care is needed |
|---|---|---|---|
| Early, limited redness on a leg, no fever, feeling well | Oral antibiotics such as flucloxacillin after photo and video assessment; pen-line monitoring; review at 48 hours[2] | Usually yes | Any spread past the line, fever, or no improvement at 48 hours |
| Larger or slowly enlarging area, still feeling well | Same-day assessment; antibiotics with a low threshold for in-person review | Sometimes, case-dependent | The doctor may direct you straight to in-person care after seeing the photos |
| Fever, chills, vomiting, or spread over hours | Same-day in-person care; intravenous antibiotics may be needed | No: triage only | Always; red streaks, confusion, a racing heart or fast breathing: call 112 |
| Redness on the face or around an eye | Urgent in-person assessment | No | Always; infection near the eye risks orbital cellulitis and is never managed remotely |
| Red, itchy, scaly skin on both lower legs, no fever | Reassessment: usually varicose eczema, treated with emollients and steroid creams, not antibiotics[1] | Usually yes | If one leg suddenly becomes hot, painful and swollen against the background |
Not sure which row is your leg? A doctor can tell you in one consultation.
See available times →Treatment options for cellulitis
What you can do yourself
Self-care runs alongside antibiotics, never instead of them. Rest with the limb raised, ideally above hip level on cushions, which eases pain and swelling noticeably; drink plenty; take paracetamol for pain and fever; and keep the pen line updated with dated photos. Do not bandage the area tightly, do not apply heat, and do not wait "one more day" if the line is being crossed. Once the infection has settled, a daily emollient keeps the skin barrier closed, and treating athlete's foot, the most common unlocked door, is the single best relapse-prevention step you control.[1]
Prescription treatment
A prescription is never issued without a consultation. After the assessment, first-line treatment for most adults is an oral anti-staphylococcal and anti-streptococcal antibiotic such as flucloxacillin, with alternatives such as clarithromycin or doxycycline where there is penicillin allergy; typical courses run 5–7 days, extended at review if healing is slow.[2] Antibiotics are only prescribed when there are genuine signs of bacterial infection; look-alike rashes leave the consultation with the treatment they actually need instead.[4] Severe cellulitis is treated with intravenous antibiotics in hospital, and no online service can substitute for that; the online doctor’s role there is recognising it fast and sending you to the right door with a clear note of what has been observed.
When cellulitis is treated online, and when you need in-person care
Treated online: early, limited cellulitis of a leg, arm or trunk in adults who feel well, with antibiotics when the doctor judges them right, and a booked 48-hour review; probable bite-reaction and varicose-eczema look-alikes, with the right non-antibiotic treatment; skin care and prevention plans after a resolved episode, including recurrent-cellulitis reviews; and the athlete's-foot treatment that closes the entry door.
In-person care: anyone with fever, chills, vomiting, confusion, a racing heart or red streaks, the same day, with 112 for sepsis warning signs; all facial and eye-area cellulitis; hand, genital and over-joint infections; suspected deep vein thrombosis; cellulitis in young children; abscesses that need drainage (see the carbuncle page for why pus needs a way out); animal and human bites and water-exposed wounds; and anyone with diabetes, immunosuppression or lymphoedema who is unwell. Escalating fast is not a failure of online care; for cellulitis, it is online care done properly.
When to get in-person care
Call 112 or go to emergency care immediately for red streaks tracking from the area toward the groin or armpit, high fever with shaking chills, confusion or drowsiness, a racing heart, fast breathing, fainting, or pain that feels far worse than the skin looks, especially with rapidly darkening, blistering or numb skin. Facial cellulitis, and any redness or swelling around an eye, needs urgent in-person assessment the same day, whatever the hour.
How Mobi Doctor works
- Book a time that suits you: open daily 7am–11pm CET. You can see a doctor over video, usually within 15 minutes. No subscription, exact price up front.
- Upload your photos, pen line included, then speak to a licensed doctor: a private video call: you describe what you feel, the doctor asks what matters, and you agree the right plan together.
- Leave with your plan: everything agreed before you hang up: your plan, and a prescription to use at a pharmacy near you where medication is clinically right for you. If your doctor decides you need to be seen in person, you get a full refund.
No sign-up needed
Not sure it’s cellulitis? Tick every symptom you have to see each condition page that mentions it. It finds the right page, not a diagnosis: a doctor gives you that on a video call. If you have an emergency sign listed on this page, call 112 instead.
Tap the body — an area or a point — to browse symptoms anywhere
Similar symptoms, different condition? Erysipelas can start the same way. Compare them, or look up any other symptom in the full symptom checker.
Frequently asked questions about cellulitis
What is cellulitis?
Cellulitis is a bacterial infection of the deeper layers of the skin and the fat beneath, most often on one lower leg, that spreads outward as a hot, red, swollen, tender area with edges that fade into normal skin. Unlike a boil, cellulitis has no single head to drain; it is treated with antibiotics, and it can make you feverish and unwell as it spreads.
What causes cellulitis?
Cellulitis is caused by bacteria, usually streptococci or Staphylococcus aureus, that live harmlessly on the skin until they get through a break in it: a cut, graze, insect bite, ulcer, surgical wound, cracked dry skin or, very commonly, athlete's foot between the toes. Leg swelling, obesity, diabetes, previous cellulitis and a weakened immune system make cellulitis more likely and more serious.
What does cellulitis look like?
Cellulitis looks like an expanding patch of red, hot, swollen, tight and tender skin, usually on one lower leg, sometimes with blisters, and often with fever, chills or feeling unwell. On darker skin the redness can be subtle, so warmth, shine, tightness and swelling are the better clues. Red streaks running from the area towards the groin or armpit mean the infection is spreading along the lymph channels.
Can an online doctor prescribe antibiotics for cellulitis in Europe?
Yes, after a consultation, for suitable cases. A prescription is never issued without one: the doctor assesses your photos and video first, and prescribes oral antibiotics when the cellulitis is limited and you are otherwise well, with a review booked for 48 hours. Any prescription can be used at a pharmacy near you, and fever, fast spread or facial cellulitis are sent to in-person care instead.
How do I know if my cellulitis is getting worse?
Use the pen line: draw round the redness, note the time, and compare at each check. Cellulitis is getting worse if the redness clearly crosses the line, you develop fever or chills, red streaks run towards the groin or armpit, the pain intensifies, or you feel increasingly unwell; any of these means in-person care now. Slight creep in the first hours after the first dose can happen before antibiotics take hold.
Is cellulitis contagious?
No, not in everyday contact. The bacteria behind cellulitis live on many healthy people's skin, and cellulitis only develops when they get through a break into the deeper layers. You cannot catch cellulitis by touching someone who has it, sharing a bed or a towel; the one sensible precaution is covering any weeping wound and washing hands after dressing it.
How can I tell cellulitis from an insect bite reaction or varicose eczema?
A bite reaction swells quickly after the bite, itches more than it hurts, and settles over a day or two in someone who feels well; cellulitis arrives later, spreads steadily, feels hot and painful, and may bring fever. Varicose eczema affects both lower legs, is itchy, scaly and long-standing, and needs moisturiser and steroid cream rather than antibiotics, whereas cellulitis is almost always one-sided.
Do I need to go to hospital for cellulitis?
Most cellulitis is treated at home with a course of tablets. Hospital and intravenous antibiotics are for cellulitis with fever and systemic upset, rapid spread, facial or eye involvement, red streaks, failure to improve after 48 hours of tablets, or in people with diabetes, a weakened immune system or severe leg swelling. The online doctor says which group you are in and where to go.
How long does cellulitis take to heal?
Most people feel cellulitis turn within 24 to 48 hours of the first antibiotic dose: pain eases, fever settles and the redness stops advancing. Antibiotic courses typically run 5 to 7 days, extended when improvement is slow, and the colour takes one to two weeks or more to fade, often with flaking skin. Swelling of the leg can persist for weeks after the infection has gone.
Why is the skin still red after finishing my antibiotics for cellulitis?
Colour fades more slowly than infection. Once the pain, heat and spread of cellulitis have resolved, the remaining pink or brownish stain can take weeks to clear, often with flaking, and that alone does not need more antibiotics. Book a review if the area is still hot, painful or enlarging, if fever returns, or if the skin breaks down, because those suggest the cellulitis is not fully treated.
What can I do at home for cellulitis?
Home care for cellulitis runs alongside antibiotics, never instead of them: rest with the leg raised above hip level on cushions, drink plenty, take paracetamol for pain and fever, moisturise the surrounding skin, and keep the pen line and dated photos updated. Do not bandage the area tightly, do not apply heat, and do not wait another day if the redness is crossing the line.
Why do I keep getting cellulitis, and how can I prevent it?
Each episode of cellulitis damages the lymph channels that drain the leg, the swelling that follows makes the next infection easier, and about 1 in 3 people have a repeat within three years. Prevent cellulitis by treating athlete's foot properly, moisturising dry skin daily, cleaning and covering cuts, managing leg swelling with compression once the infection has cleared, and, after two or more episodes, asking about low-dose preventive antibiotics.
Is cellulitis more dangerous with diabetes, in pregnancy or in older people?
Yes. With diabetes, cellulitis of the foot can hide a deeper infection or ulcer and spreads faster, so the threshold for in-person care is low. In pregnancy, cellulitis is treated with antibiotics safe in pregnancy and fever is always reviewed promptly. Older people more often have leg swelling, thin skin and fewer warning symptoms, so confusion or going off food can be the first sign that cellulitis is serious.
- Cellulitis, acute: Clinical Knowledge Summary, NICE Clinical Knowledge Summaries, revised 2024.
- Cellulitis and erysipelas: antimicrobial prescribing (NG141), National Institute for Health and Care Excellence, 2019.
- Cellulitis, DermNet New Zealand Trust, updated 2023.
- Antimicrobial resistance: fact sheet, World Health Organization, 2023.
- Cellulitis, HSE, Health Service Executive (Ireland), accessed August 2026.
- Cellulitis, NHS, National Health Service (UK), accessed October 2026.
This page is for information only and is not a substitute for a medical consultation. Guideline links are provided for transparency; treatment decisions are made with your doctor.
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