# Cellulitis

> Cellulitis is a bacterial infection of the skin that makes it red, hot, swollen and painful, most often on a lower leg. Suspected cellulitis needs urgent medical assessment, usually the same day, and often antibiotics. It can come back, so looking after leg swelling and skin matters.

Guide in [Skin and nails](https://footanklelowerlimb.com.au/learn/topics/skin-and-nails), from Foot Ankle Lower Limb: https://footanklelowerlimb.com.au/learn/cellulitis
Reviewed by Andrew Schox, BSc(Hons) PGradDipPod MPod (Podiatrist) on 27 October 2026.
Next review by 27 October 2027.

- **It's a bacterial skin infection** that makes skin red, hot, swollen and painful, most often on a lower leg.
- **It needs urgent medical assessment,** usually the same day, and often antibiotics.
- **Breaks in the skin raise the risk,** including cracks from athlete's foot.
- **It can come back,** and managing leg swelling can help reduce that.
- **A few signs mean an ambulance,** and they're listed at the end.

## What is cellulitis?

Cellulitis is an acute bacterial infection of the skin and the tissue just beneath it [1]. It's a common skin infection [2]. The lower leg is the most usual place, but any area of skin can be affected, including the foot [3].

## What causes it, and who gets it?

The bacteria that cause cellulitis often live harmlessly on your skin. They can cause infection if they get into a break such as a bruise, cut, graze, or an animal or insect bite [4]. A leg ulcer, or dry, cracked skin from eczema or athlete's foot, can also let them in. Often the trigger is never found [4]. Group A streptococcus and Staphylococcus aureus are the most common germs involved [5].

Your risk is higher with a fungal infection of the foot (a strong link), cracks on the soles, leg swelling, leg ulcers or a past injury [6]. Obesity, lymphoedema (swelling from a damaged lymph drainage system), poorly controlled diabetes, eczema and liver disease also raise it [7].

## What does it feel like, and how is it diagnosed?

Cellulitis is diagnosed from how the skin looks and feels: redness, swelling, warmth and tenderness in one area [8]. The skin is painful, hot and swollen and usually looks red, though redness may be less obvious on brown or black skin. It may blister, and you can have flu-like symptoms with swollen, painful glands [9]. The skin may look tight and glossy [10].

Other problems can look similar, and a wrong diagnosis leads to antibiotics that aren't needed. If the picture isn't typical, a doctor may ask for a dermatology (skin) opinion [2].

## What helps first?

Cellulitis needs medical care from the start, not home treatment. It often needs antibiotics [2], and a doctor decides which medicine and for how long. Your doctor may mark the edge of the redness with a pen to see whether it spreads over the next few days [10]. If you haven't started to feel better after two full days of treatment, contact your doctor [11].

> [!tip] Try this
> Mark the edge of the redness with a pen and write down the date and time. Check each day whether the redness goes past the line. If it does, see your GP the same day.

## What helps if that isn't enough?

If you haven't started to improve within 2–3 days, or the redness or swelling is spreading, you need to be reassessed by a doctor [12]. A swab from broken skin may be taken to look for the germ if antibiotics aren't working [12]. Hospital care is advised for sepsis, a weakened immune system, home treatment that hasn't worked, or difficulty keeping up with treatment [13].

## Can it come back, and how can I prevent that?

Cellulitis can come back. Each episode is thought to damage the lymph vessels (the channels that drain fluid), which raises the risk of later episodes [7]. Lymphoedema, obesity and a history of cancer are the main general risk factors for repeat cellulitis [6].

If you have lymphoedema, managing it, particularly with compression, consistently reduced repeat cellulitis [14]. Check with your doctor when compression is right for you. Keep treating athlete's foot and wounds, as guidelines recommend; it isn't clear yet whether this prevents repeat episodes [14]. If it keeps coming back, talk to your doctor about your options.

## When to see a podiatrist

Suspected cellulitis needs urgent medical assessment: see your GP the same day. A podiatrist can look at a red, hot or swollen foot, but you will usually need a doctor for treatment.

Call 000 and ask for an ambulance if you feel very unwell with signs of sepsis (confusion or slurred speech, mottled skin, little or no urine, severe breathlessness), or if the skin turns dusky, purple or blistered with severe pain [15][16].

These also need urgent medical assessment. See your GP the same day, or go to a Medicare Urgent Care Clinic or the emergency department if you can't:

- redness or swelling that is spreading, especially quickly [1];
- a fever, shaking, vomiting, dizziness, a fast heartbeat, or cold, sweaty skin [4][11];
- severe pain, or pain out of proportion to how the skin looks [1][12];
- no improvement after two full days of antibiotics [11];
- red streaks, blistering over the area, drowsiness or a fever that won't settle [10];
- redness on the face or around the eye (go straight to the emergency department) [4];
- a human or animal bite, diabetes, a weakened immune system, severe lymphoedema or smoking [5][4][1].

A baby under one, or a frail or immunocompromised person, with cellulitis should see a GP the same day [1]. The same goes for a young child or an older person [4].

For urgent advice when it isn't an emergency, call healthdirect on 1800 022 222 (24 hours a day), or go to a Medicare Urgent Care Clinic.

## Common questions

### Can athlete's foot lead to cellulitis?

It can raise the risk. A fungal infection of the foot has a strong link with cellulitis, and the dry, cracked skin it causes can let bacteria in. Check between your toes and on your soles for cracks or peeling. A pharmacist or podiatrist can advise on treating athlete's foot.

### What does cellulitis look like on darker skin?

Redness may be less obvious on brown or black skin, so look for other changes too. The area is usually hot, swollen and painful, and it may blister. Comparing the sore area with the same spot on your other leg can help you notice a difference. Any of these signs means seeing your GP the same day.

### How is cellulitis different from erysipelas?

Erysipelas is a more superficial skin infection, usually caused by streptococcal bacteria. It has sharply edged borders and develops faster than cellulitis. The two are hard to tell apart, and erysipelas is treated in the same way as cellulitis. Either way, see your GP the same day.

## Further reading

- [Cellulitis on Clindice](https://clindice.com/cellulitis)
- [Cellulitis](https://www.nhs.uk/conditions/cellulitis/), NHS
- [SKIN AND SOFT TISSUE INFECTIONS Cellulitis](https://www.nottsapc.nhs.uk/media/5djlslvw/cellulitis.pdf), NHS
- [Display Patient Information Leaflets](https://www.plymouthhospitals.nhs.uk/display-pil/pil-cellulitis-management-8548/), NHS
- [Cellulitis | Recent Illness or Concern | Child 5 - 11 years | Healthier Together](https://www.healthiertogether.nhs.uk/child-under-12-years/cellulitis), NHS
- [Cellulitis and how we treat it - Buckinghamshire Healthcare NHS Trust](https://www.buckshealthcare.nhs.uk/pifs/cellulitis-and-how-we-treat-it-2/), NHS

## Sources

1. SKIN AND SOFT TISSUE INFECTIONS Cellulitis · NHS. https://www.nottsapc.nhs.uk/media/5djlslvw/cellulitis.pdf
2. Diagnostic stewardship and dermatology consultation in cellulitis management: a systematic literature review and meta-analysis · Lin V, Callado GY, Pardo I et al. · Archives of Dermatological Research · 2024. https://doi.org/10.1007/s00403-024-03515-x
3. Display Patient Information Leaflets · University Hospitals Plymouth NHS Trust · 2022. https://www.plymouthhospitals.nhs.uk/display-pil/pil-cellulitis-6088/
4. Cellulitis · nidirect. https://www.nidirect.gov.uk/conditions/cellulitis
5. Cellulitis - symptoms, treatment and causes · Healthdirect Australia. https://www.healthdirect.gov.au/conditions/skin-conditions/cellulitis
6. Interventions for the prevention of recurrent erysipelas and cellulitis · Dalal A, Eskin-Schwartz M, Mimouni D et al. · The Cochrane Database of Systematic Reviews · 2017. https://doi.org/10.1002/14651858.cd009758.pub2
7. Recurrent Erysipelas: Clinical Challenges and Strategies for Prevention-A Narrative Literature Review · Jaskóła-Polkowska DM, Blok K, Skibińska A et al. · Biomedicines · 2025. https://doi.org/10.3390/biomedicines13102448
8. Cellulitis · Bystritsky RJ · Infectious Disease Clinics of North America · 2021. https://doi.org/10.1016/j.idc.2020.10.002
9. Cellulitis · NHS · 2017. https://www.nhs.uk/conditions/cellulitis/
10. Cellulitis: MedlinePlus Medical Encyclopedia · National Institutes of Health · 2025. https://www.nlm.nih.gov/medlineplus/ency/article/000855.htm
11. Display Patient Information Leaflets · University Hospitals Plymouth NHS Trust · 2025. https://www.plymouthhospitals.nhs.uk/display-pil/pil-cellulitis-management-8548/
12. Management of cellulitis and erysipelas - South & West · South & West. https://southwest.devonformularyguidance.nhs.uk/formulary/chapters/5-infections/skin-and-soft-tissue-infections/cellulitis-erysipelas
13. Advances in the diagnosis and management of skin and soft tissue infections · Long B, Yadav K, Rech MA et al. · BMJ (Clinical Research Ed.) · 2026. https://doi.org/10.1136/bmj-2026-100580
14. Secondary prevention of cellulitis: A systematic review · Sierla R, Fearn N, Nube V et al. · Phlebology · 2026. https://doi.org/10.1177/02683555251398389
15. GUIDELINE FOR OUTPATIENT PARENTERAL ANTIBIOTIC · NHS. https://www.dbth.nhs.uk/wp-content/uploads/2026/06/OPAT_Guideline_2026-FINAL.pdf
16. Lower limb cellulitis · Gloucestershire Hospitals NHS Foundation Trust. https://www.gloshospitals.nhs.uk/your-visit/patient-information-leaflets/lower-limb-cellulitis/

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This page is general information, not a diagnosis or a treatment plan for you. For advice about your own feet or legs, see a podiatrist or your doctor. In an emergency, call 000.