Page last updated:
13th June 2023


Overview – hot, swollen, tender red legs could be a sign of cellulitis

When our legs are swollen or we have other skin problems, our legs can sometimes become hot, inflamed (red) and tender. Cellulitis is an acute spreading inflammation of the skin and subcutaneous tissues characterised by pain, warmth, swelling and erythema. Cellulitis typically only occurs in one leg.

Symptoms – what are the symptoms of cellulitis?

The signs of cellulitis vary but things to look out for include:

  • Redness
  • New or an increase in swelling
  • Pain or tenderness
  • Increased temperature in the area – the skin will feel ‘hot’ or like it’s burning
  • Feeling generally unwell and ‘fluey’ is a common symptom, sometimes starting a few days before other symptoms

These symptoms can happen any time our lower legs and feet are swollen.

Sometimes infections are caused by damage to the skin such as a burn, cut, insect bite or even athlete’s foot. But often there isn’t always a visible trigger or cause of the infection. Cellulitis can be serious. If it is suspected the GP practice should be contacted promptly to get the correct diagnosis and start treatment as soon as possible.

What does cellulitis look like?

Image of Cellulitis on the leg for Legs Matter

It is very unusual for cellulitis to affect both legs at the same time so if there is redness, pain and swelling in both legs, it is unlikely to be cellulitis. Cellulitis makes your skin painful, hot and swollen. The area typically  looks red, but this may be less obvious on brown or black skin. It may be another condition commonly called red legs syndrome. For more information download the BLS Red Legs Pathway notes (PDF).

Causes – what can cause cellulitis

A common cause of this is a bacterial infection of the skin called cellulitis. Swollen legs are more likely to get cellulitis because the lymph system is damaged or impaired and is not as good at preventing infection. Cellulitis typically only occurs in one leg.

Carl's story
Read Carl's cellulitis and leg ulcer story – he's a father of three, is 48 and lives in Banbury, Oxfordshire

Diagnosis – getting diagnosed with cellulitis

If you think you might have cellulitis it is important to get help straight away, especially if this is the first time you have had this problem. Ask for a same-day appointment with your GP. If the symptoms begin over a weekend, contact your out-of-hours GP service or NHS 111 or attend your local A&E.

The doctor or nurse will look at the affected area and make a note of the colour, swelling and temperature. They might also mark the area on your leg so it’s easier to see if your infection is getting better once you start treatment. They will also look for any wounds or other skin damage that might have caused the infection.

Most cellulitis infections are diagnosed by examining the leg or foot, but the doctor or nurse may also take your temperature or carry out some blood tests to confirm diagnosis. Cellulitis infections can look similar to blood clots (deep vein thrombosis or DVT) because of increased redness and swelling in one leg. Cellulitis can be confused with haemosiderin staining but this is redness without a temperature and should not be tender to the touch; another clue is that haemosiderin staining will not reduce or resolve with antibiotics. Your doctor or nurse might refer you to the hospital to get further tests to make sure you get the correct diagnosis and treatment.

What to expect at your appointment

Cellulitis can be difficult to diagnose and to distinguish from other causes of inflammation in the legs but cellulitis most commonly affects one leg only. If you have bilateral ‘red legs’, it is likely to be associated with venous hypertension / insufficiency, swollen legs, and / or haemosiderin).

In lymphoedema / chronic oedema, attacks of cellulitis vary in presentation and may differ from classical cellulitis.

  • Some episodes are accompanied by severe systemic upset, with high fever and rigors; others are milder, with minimal or no fever
  • Increased swelling of the affected area may occur
  • Inflammatory markers (CRP, ESR) may be raised

Your initial assessment should include a baseline record to include the following:

  • Extent and severity of rash – if possible, mark and date the edge of the erythema (this may be difficult in lymphoedema as the rash is often blotchy)
  • Level of systemic upset
  • Note history of repeated cellulitis, often a sign of unmanaged swelling
  • CRP / ESR / white cell count – these may be helpful in diagnosis and monitoring of treatment
  • Microbiology of any cuts or breaks in the skin – this should be considered before antibiotics are started.

You should decide whether hospital admission is required by:

  • The level of systemic upset and any signs of septicaemia
  • Whether symptoms are worsening despite treatment

Treatment – what treatment will I be offered for cellulitis?

Antibiotic therapy

Cellulitis infections need a course of antibiotics to clear the infection. Most infections go away with a course of oral (tablet) antibiotics that you can take at home but occasionally you might be admitted to hospital for intra-venous (IV) antibiotics.

Your symptoms may get worse in the first 48 hours of treatment, but should then start to improve. If you are unsure, call 111 if you can’t speak to your GP if you don’t know what to do next.

It is important that you finish the whole course of antibiotics. The length of antibiotic course for cellulitis, especially if you have swollen legs, is often longer than antibiotic courses for other infections. Sometimes a second antibiotic course or an extended course of antibiotics is needed just to make sure the infection has completely gone.

Managing pain

The infected area can be painful. Pain killers such as paracetamol may be helpful along with rest and elevating your swollen leg or foot. Often people need time off work so you might need a sick note from your GP.

Things you can do yourself

As well as taking antibiotics, you can help speed up your recovery by looking after your general well being. There are some approaches you can read on the NHS Choices’ website.

Remember that cellulitis is usually due to unmanaged swelling. If you normally wear a compression garment it might be too painful to wear during the infection. If it is, take it off – y­ou can start wearing it again when the swelling and pain has reduced. You might need a different size stocking if the swelling has got worse during the infection.

But it is important to return to this important therapy as soon as you can. The team that provide your compression care and treatment will want to know about the infection so they can arrange a review appointment and make sure you are wearing the right compression garment.

Skin care

Your legs can become dry during and after the infection so make sure you keep them moisturised. Using an unperfumed moisturiser is better for your skin. There may be blisters or wounds that need dressing or monitoring by a nursing team so keep an eye out for those.

Prevention – what can you do to prevent

Skin care

Your legs can become dry during and after the infection so make sure you keep them moisturised. Using an unperfumed moisturiser is better for your skin. There may be blisters or wounds that need dressing or monitoring by a nursing team so keep an eye out for those.

Reducing the risk of recurrence

The risk of further attacks of cellulitis in lymphoedema is high. Risk factors for recurrence of cellulitis in lymphoedema include:

  • Swelling
  • Cracked, macerated, inter-digital skin
  • Dermatitis
  • Open wounds including leg ulcers and weeping lymphangiectasia (leaking lymph blisters on the skin surface)
  • Inadequate compression therapy

Make sureany possible underlying fungal infection is treated and this will help to prevent recurrence.

Decongestive lymphatic therapy (DLT)

Lymphoedema treatment (decongestive lymphatic therapy – DLT) is thought to reduce the frequency of attacks.

Prophylactic antibiotic therapy

If you have had an attack of cellulitis, you should carry a 2 week supply of antibiotics with you particularly when away from home for any length of time, eg on holiday. You should start antibiotics immediately if you observe familiar symptoms of cellulitis develop, but do seek a medical opinion as soon as possible.

If you have had two or more attacks of cellulitis per year your may be given antibiotics prophylactically. It may not be possible to fully prevent further episodes of cellulitis even with prophylactic antibiotics, however, there may be a reduction in the frequency of cellulitis and / or the severity of episodes.

Following two years of successful prophylaxis, it may be discontinued, particularly if the risk factors have been successfully addressed. However, if you have ongoing significant risk factors, continuing prophylaxis may be considered. Prophylaxis may need to be lifelong you have a relapse occurs after prophylactic antibiotics are discontinued.

Where’s the harm?

  • Failure to treat cellulitis promptly may lead to septicaemia, which is life-threatening
  • Failure to treat cellulitis adequately may lead to a cycle of apparently recurrent infections (when it is really a resurgence of the same infection), overuse of antibiotics and increasing damage to the lymphatic system, causing unnecessary pain and suffering. This is also wasteful of NHS resources.
  • Confusing cellulitis with red legs syndrome or haemosiderin stain causes overuse of antibiotics and risks them being ineffective should they really be required in the future

Other support

The British Lymphology Society (BLS) is a dynamic and innovative body providing a strong professional voice and support for those involved in the care and treatment of people with lymphoedema and related lymphatic disorders, including lipoedema.

Contact details
01452 790178
Find out more on the British Lymphology Society website

Lymphoedema Support Network (LSN) is a national UK charity which provides information and support to people with lymphoedema.

Contact details
020 7351 0990
Find out more on the Lymphoedema Support Network website

NHS Choices the official NHS website, which provides vital information and support about leg and foot signs and other symptoms.

Contact details
Call 111 - for non-emergency medical advice
Find out more on the NHS Choices website

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