Recommendations

1.1 Managing cellulitis and erysipelas

Treatment

1.1.1 To ensure that cellulitis and erysipelas are treated appropriately, exclude other causes of skin redness such as:

  • an inflammatory reaction to an immunisation or an insect bite or

  • a non-infectious cause such as chronic venous insufficiency.

1.1.2 Consider taking a swab for microbiological testing from people with cellulitis or erysipelas to guide treatment, but only if the skin is broken and:

  • there is a penetrating injury or

  • there has been exposure to water-borne organisms or

  • the infection was acquired outside the UK.

1.1.3 Before treating cellulitis or erysipelas, consider drawing around the extent of the infection with a single-use surgical marker pen to monitor progress. Be aware that redness may be less visible on darker skin tones.

1.1.4 Offer an antibiotic for people with cellulitis or erysipelas. When choosing an antibiotic (see the recommendations on choice of antibiotic), take account of:

  • the severity of symptoms

  • the site of infection (for example, near the eyes or nose)

  • the risk of uncommon pathogens (for example, from a penetrating injury, after exposure to water-borne organisms, or an infection acquired outside the UK)

  • previous microbiological results from a swab

  • the person's meticillin-resistant Staphylococcus aureus (MRSA) status if known.

1.1.5 Give oral antibiotics first line if the person can take oral medicines, and the severity of their condition does not require intravenous antibiotics.

1.1.6 If intravenous antibiotics are given, review by 48 hours and consider switching to oral antibiotics if possible.

1.1.7 Manage any underlying condition that may predispose to cellulitis or erysipelas, for example:

  • diabetes

  • venous insufficiency

  • eczema

  • oedema, which may be an adverse effect of medicines such as calcium channel blockers.

Advice

1.1.8 When prescribing antibiotics for cellulitis or erysipelas, give advice about:

  • possible adverse effects of antibiotics

  • the skin taking some time to return to normal after the course of antibiotics has finished

  • seeking medical help if symptoms worsen rapidly or significantly at any time, or do not start to improve within 2 to 3 days.

Reassessment

1.1.9 Reassess people with cellulitis or erysipelas if symptoms worsen rapidly or significantly at any time, do not start to improve within 2 to 3 days, or the person:

1.1.10 When reassessing people with cellulitis or erysipelas, take account of:

  • other possible diagnoses, such as an inflammatory reaction to an immunisation or an insect bite, gout, superficial thrombophlebitis, eczema, allergic dermatitis or deep vein thrombosis

  • any underlying condition that may predispose to cellulitis or erysipelas, such as oedema, diabetes, venous insufficiency or eczema

  • any symptoms or signs suggesting a more serious illness or condition, such as lymphangitis, orbital cellulitis, osteomyelitis, septic arthritis, necrotising fasciitis or sepsis

  • any results from microbiological testing

  • any previous antibiotic use, which may have led to resistant bacteria.

1.1.11 Consider taking a swab for microbiological testing from people with cellulitis or erysipelas if the skin is broken and this has not been done already.

1.1.12 If a swab has been sent for microbiological testing:

  • review the choice of antibiotic(s) when results are available and

  • change the antibiotic(s) according to results if symptoms or signs of the infection are not improving, using a narrow-spectrum antibiotic if possible.

Referral and seeking specialist advice

1.1.13 Refer people to hospital if they have any symptoms or signs suggesting a more serious illness or condition, such as orbital cellulitis, osteomyelitis, septic arthritis, necrotising fasciitis or sepsis.

1.1.14 Consider referring people with cellulitis or erysipelas to hospital, or seek specialist advice, if they:

  • are severely unwell or

  • have infection near the eyes or nose (including periorbital cellulitis) or

  • could have uncommon pathogens, for example, after a penetrating injury, exposure to water-borne organisms, or an infection acquired outside the UK or

  • have spreading infection that is not responding to oral antibiotics or

  • lymphangitis or

  • cannot take oral antibiotics (exploring locally available options for giving intravenous antibiotics at home or in the community, rather than in hospital, where appropriate).

For a short explanation of why the committee made these recommendations, see the summary of the evidence on managing cellulitis and erysipelas.

1.2 Choice of antibiotic

1.2.1 When prescribing an antibiotic for cellulitis or erysipelas, follow:

  • table 1 for adults aged 18 years and over

  • table 2 for children and young people under 18 years.

Table 1 Antibiotics for adults aged 18 years and over

Treatment

Antibiotic, dosage and course length

First-choice antibiotic (give orally unless person unable to take oral or severely unwell)

Flucloxacillin (5 to 7 days):

500 mg to 1 g four times a day orally

or 1 g to 2 g four times a day intravenously

In September 2019, 1 g orally four times a day was off label. See NICE's information on prescribing medicines.

Alternative first-choice antibiotics for penicillin allergy or if flucloxacillin is unsuitable (give orally unless person unable to take oral or severely unwell)

Clarithromycin (5 to 7 days):

500 mg twice a day orally

or 500 mg twice a day intravenously

Erythromycin (in pregnancy; 5 to 7 days):

500 mg four times a day orally

Doxycycline (5 to 7 days in total):

200 mg on the first day then 100 mg once a day orally

First-choice antibiotic if infection is near the eyes or nose (consider seeking specialist advice; give orally unless person unable to take oral or severely unwell)

Co‑amoxiclav (7 days):

500/125 mg three times a day orally

or 1.2 g three times a day intravenously

Alternative first-choice antibiotics if infection is near the eyes or nose for penicillin allergy or if co‑amoxiclav is unsuitable (consider seeking specialist advice; give orally unless person unable to take oral or severely unwell)

Clarithromycin (7 days):

500 mg twice a day orally

or 500 mg twice a day intravenously

with

Metronidazole (7 days):

400 mg three times a day orally

or 500 mg three times a day intravenously

Alternative choice antibiotics for severe infection

Co‑amoxiclav (7 days):

500/125 mg three times a day orally

or 1.2 g three times a day intravenously

Cefuroxime (7 days):

750 mg to 1.5 g three or four times a day intravenously

Clindamycin (7 days):

150 mg to 300 mg four times a day (can be increased to 450 mg four times a day) orally

or 600 mg to 2.7 g daily intravenously in two to four divided doses, increased if necessary in life-threatening infection to 4.8 g daily (maximum per dose 1.2 g)

Ceftriaxone (7 days; only for ambulatory care; other antibiotics may be appropriate based on microbiological results and specialist advice):

2 g once a day intravenously

Antibiotics to be added if meticillin-resistant Staphylococcus aureus infection is suspected or confirmed (combination therapy with an antibiotic listed above; other antibiotics may be appropriate based on microbiological results and specialist advice)

Vancomycin:

15 mg/kg to 20 mg/kg two or three times a day intravenously (maximum 2 g per dose), adjusted according to serum vancomycin concentration (see the British national formulary [BNF] for information on monitoring)

Teicoplanin:

Initially 6 mg/kg every 12 hours for three doses, then 6 mg/kg once a day intravenously (see the BNF for information on monitoring)

Linezolid (if vancomycin or teicoplanin cannot be used; specialist use only):

600 mg twice a day orally or

600 mg twice a day intravenously (see the BNF for information on monitoring)

See the BNF for appropriate use and dosing in specific populations, for example, people with hepatic or renal impairment, in pregnancy and breastfeeding, and when administering intravenous (or, where appropriate, intramuscular) antibiotics.

Give oral antibiotics first line if the person can take oral medicines, and the severity of their symptoms does not warrant intravenous antibiotics. If intravenous antibiotics are given, review by 48 hours and consider switching to oral antibiotics, if possible.

A longer course length (up to 14 days in total) may be needed based on clinical assessment. However, skin does take some time to return to normal, and full resolution of symptoms at 5 to 7 days is not expected.

Infection around the eyes or the nose (the triangle from the bridge of the nose to the corners of the mouth, or immediately around the eyes including periorbital cellulitis) is of more concern because of risk of a serious intracranial complication.

Erythromycin is preferred if a macrolide is needed in pregnancy, for example, if there is true penicillin allergy and the benefits of antibiotic treatment outweigh the harms. See the Medicines and Healthcare products Regulatory Agency (MHRA) Public Assessment Report on the safety of macrolide antibiotics in pregnancy.

Table 2 Antibiotics for children and young people under 18 years

Treatment

Antibiotic, dosage and course length

Children under 1 month

Antibiotic choice based on specialist advice

First-choice antibiotic for children aged 1 month and over (give orally unless person unable to take oral or severely unwell)

Flucloxacillin (5 to 7 days):

1 month to 1 year, 62.5 mg to 125 mg four times a day orally

2 years to 9 years, 125 mg to 250 mg four times a day orally

10 years to 17 years, 250 mg to 500 mg four times a day orally

or 1 month to 17 years, 12.5 mg/kg to 25 mg/kg four times a day intravenously (maximum 1 g four times a day)

Alternative first-choice antibiotics for penicillin allergy or if flucloxacillin unsuitable (give orally unless person unable to take oral or severely unwell)

Co‑amoxiclav (not in penicillin allergy; 5 to 7 days):

1 month to 11 months, 0.25 ml/kg of 125/31 suspension three times a day orally (dose doubled in severe infection)

1 year to 5 years, 0.25 ml/kg or 5 ml of 125/31 suspension three times a day orally (dose doubled in severe infection)

6 years to 11 years, 0.15 ml/kg or 5 ml of 250/62 suspension three times a day orally (dose doubled in severe infection)

12 years to 17 years, 250/125 mg or 500/125 mg three times a day orally

or 1 month to 2 months, 30 mg/kg twice a day intravenously

3 months to 17 years, 30 mg/kg three times a day intravenously (maximum 1.2 g three times a day)

Clarithromycin (5 to 7 days):

1 month to 11 years:

under 8 kg, 7.5 mg/kg twice a day orally

8 kg to 11 kg, 62.5 mg twice a day orally

12 kg to 19 kg, 125 mg twice a day orally

20 kg to 29 kg, 187.5 mg twice a day orally

30 kg to 40 kg, 250 mg twice a day orally

12 years to 17 years, 250 mg to 500 mg twice a day orally

or 1 month to 11 years, 7.5 mg/kg twice a day intravenously (maximum 500 mg per dose)

12 years to 17 years, 500 mg twice a day intravenously

Erythromycin (in pregnancy; 5 to 7 days):

8 years to 17 years, 250 mg to 500 mg four times a day orally

First-choice antibiotic if infection near the eyes or nose (consider seeking specialist advice; give orally unless person unable to take oral or severely unwell)

Co‑amoxiclav (7 days):

1 month to 11 months, 0.25 ml/kg of 125/31 suspension three times a day orally (dose doubled in severe infection)

1 year to 5 years, 0.25 ml/kg or 5 ml of 125/31 suspension three times a day orally (dose doubled in severe infection)

6 years to 11 years, 0.15 ml/kg or 5 ml of 250/62 suspension three times a day orally (dose doubled in severe infection)

12 years to 17 years, 250/125 mg or 500/125 mg three times a day orally

or 1 month to 2 months, 30 mg/kg twice a day intravenously

3 months to 17 years, 30 mg/kg three times a day intravenously (maximum 1.2 g three times a day)

Alternative first-choice antibiotics if infection near the eyes or nose for penicillin allergy or if co‑amoxiclav unsuitable (consider seeking specialist advice; give orally unless person unable to take oral or severely unwell)

Clarithromycin (7 days):

1 month to 11 years:

under 8 kg, 7.5 mg/kg twice a day orally

8 kg to 11 kg, 62.5 mg twice a day orally

12 kg to 19 kg, 125 mg twice a day orally

20 kg to 29 kg, 187.5 mg twice a day orally

30 kg to 40 kg, 250 mg twice a day orally

12 years to 17 years, 250 mg to 500 mg twice a day orally

or 1 month to 11 years, 7.5 mg/kg twice a day intravenously (maximum 500 mg per dose)

12 years to 17 years, 500 mg twice a day intravenously

with (if anaerobes suspected)

Metronidazole (7 days):

1 month, 7.5 mg/kg twice a day orally

2 months to 11 years, 7.5 mg/kg three times a day orally (maximum per dose 400 mg)

12 years to 17 years, 400 mg three times a day orally

or 1 month, loading dose 15 mg/kg, then (after 8 hours) 7.5 mg/kg three times a day intravenously

2 months to 17 years, 7.5 mg/kg three times a day intravenously (maximum per dose 500 mg)

Alternative choice antibiotics for severe infection (other antibiotics may be appropriate based on microbiological results and specialist advice)

Co‑amoxiclav (7 days):

1 month to 11 months, 0.25 ml/kg of 125/31 suspension three times a day orally (dose can be doubled)

1 year to 5 years, 0.25 ml/kg or 5 ml of 125/31 suspension three times a day orally (dose can be doubled)

6 years to 11 years, 0.15 ml/kg or 5 ml of 250/62 suspension three times a day orally (dose can be doubled)

12 years to 17 years, 250/125 mg or 500/125 mg three times a day orally

or 1 month to 2 months, 30 mg/kg twice a day intravenously

3 months to 17 years, 30 mg/kg three times a day intravenously (maximum 1.2 g three times a day)

Cefuroxime (7 days):

1 month to 17 years, 20 mg/kg three times a day intravenously (maximum 750 mg per dose), can be increased to 50 mg/kg to 60 mg/kg three or four times a day intravenously (maximum 1.5 g per dose)

Clindamycin (7 days):

1 month to 17 years, 3 mg/kg to 6 mg/kg four times a day orally (maximum per dose 450 mg)

or 1 month to 17 years, 3.75 mg/kg to 6.25 mg/kg four times a day intravenously, increased if necessary, in life-threatening infection to 10 mg/kg four times a day intravenously (maximum per dose 1.2 g); total daily dose may alternatively be given in three divided doses (maximum per dose 1.2 g)

Antibiotics to be added if meticillin-resistant Staphylococcus aureus infection is suspected or confirmed (combination therapy with an antibiotic listed above; other antibiotics may be appropriate based on microbiological results and specialist advice)

Vancomycin:

1 month to 11 years, 10 mg/kg to 15 mg/kg four times a day intravenously, adjusted according to serum vancomycin concentration

12 years to 17 years, 15 mg/kg to 20 mg/kg two or three times a day intravenously (maximum 2 g per dose), adjusted according to serum vancomycin concentration

(see the British national formulary for children [BNFC] for information on monitoring)

Teicoplanin:

1 month, initially 16 mg/kg for one dose, then (after 24 hours) 8 mg/kg once a day intravenously

2 months to 11 years, initially 10 mg/kg every 12 hours for three doses, then 6 mg/kg to 10 mg/kg once a day intravenously

12 years to 17 years, initially 6 mg/kg every 12 hours for three doses, then 6 mg/kg once a day intravenously

(see the BNFC for information on monitoring)

Linezolid (if vancomycin or teicoplanin cannot be used; specialist use only):

1 month to 11 years, 10 mg/kg three times a day orally (maximum 600 mg per dose)

12 years to 17 years, 600 mg twice a day orally

or 1 month to 11 years, 10 mg/kg three times a day intravenously (maximum 600 mg per dose)

12 years to 17 years, 600 mg twice a day intravenously

In September 2019, the use of linezolid in children and young people under 18 years was off label. See NICE's information on prescribing medicines.

(see the BNFC for information on monitoring)

See the BNFC for appropriate use and dosing in specific populations, for example, people with hepatic or renal impairment, in pregnancy and breastfeeding, and when administering intravenous (or, where appropriate, intramuscular) antibiotics.

The age bands apply to children of average size and, in practice, the prescriber will use the age bands with other factors, such as the severity of the condition and the child's size in relation to the average size of children of the same age.

Give oral antibiotics first line if the person can take oral medicines, and the severity of their symptoms does not warrant intravenous antibiotics. If intravenous antibiotics are given, review by 48 hours and consider switching to oral antibiotics, if possible.

A longer course length (up to 14 days in total) may be needed based on clinical assessment. However, skin does take some time to return to normal, and full resolution of symptoms at 5 to 7 days is not expected.

If flucloxacillin oral solution is not tolerated because of poor palatability, consider capsules (see the Medicines for Children leaflet on helping your child to swallow tablets).

Co‑amoxiclav 400/57 suspension may also be considered to allow twice daily dosing (see the BNFC for dosing information).

Infection around the eyes or the nose (the triangle from the bridge of the nose to the corners of the mouth, or immediately around the eyes including periorbital cellulitis) is of more concern because of risk of a serious intracranial complication.

Erythromycin is preferred if a macrolide is needed in pregnancy, for example, if there is true penicillin allergy and the benefits of antibiotic treatment outweigh the harms. See the Medicines and Healthcare products Regulatory Agency (MHRA) Public Assessment Report on the safety of macrolide antibiotics in pregnancy.

For a short explanation of why the committee made this recommendation, see the summary of the evidence on choice of antibiotics, antibiotic dose frequency, antibiotic course length and antibiotic route of administration.

Full details of the evidence are in the evidence review.

1.3 Preventing recurrent cellulitis or erysipelas

1.3.1 Do not routinely offer antibiotic prophylaxis to prevent recurrent cellulitis or erysipelas. Give advice about seeking medical help if symptoms of cellulitis or erysipelas develop.

1.3.2 For adults who have had treatment in hospital, or under specialist advice, for at least 2 separate episodes of cellulitis or erysipelas in the previous 12 months, specialists may consider a trial of antibiotic prophylaxis. Involve the person in a shared decision by discussing and taking account of:

  • the severity and frequency of previous symptoms

  • the risk of developing complications

  • underlying conditions (such as oedema, diabetes or venous insufficiency) and their management

  • the risk of resistance with long-term antibiotic use

  • the person's preference for antibiotic use.

1.3.3 When choosing an antibiotic for prophylaxis (see the recommendations on choice of antibiotic prophylaxis), take account of any previous microbiological results and previous antibiotic use.

1.3.4 When antibiotic prophylaxis is given, give advice about:

  • possible adverse effects of long-term antibiotics

  • returning for review within 6 months

  • seeking medical help if symptoms of cellulitis or erysipelas recur.

1.3.5 Review antibiotic prophylaxis for recurrent cellulitis or erysipelas at least every 6 months. The review should include:

  • assessing the success of prophylaxis

  • discussing continuing, stopping or changing prophylaxis (taking into account the person's preferences for antibiotic use and the risk of antimicrobial resistance).

    Stop or change the prophylactic antibiotic to an alternative if cellulitis or erysipelas recurs (see recommendation 1.1.4 in the section on treatment for treatment of acute infection).

For a short explanation of why the committee made these recommendations, see the summary of the evidence on antibiotic prophylaxis for the prevention of recurrent cellulitis and erysipelas.

Full details of the evidence are in the evidence review.

1.4 Choice of antibiotic prophylaxis

1.4.1 When prescribing an antibiotic to prevent recurrent cellulitis or erysipelas in adults, specialists should follow table 3.

Table 3 Antibiotic prophylaxis for adults 18 years and over

Prophylaxis

Antibiotic and dosage

First choice

Choose antibiotics according to recent microbiological results when possible, and avoid using the same antibiotic for treatment and prophylaxis

Phenoxymethylpenicillin:

250 mg orally twice a day

Alternative first choice for penicillin allergy

Choose antibiotics according to recent microbiological results when possible, and avoid using the same antibiotic for treatment and prophylaxis

Erythromycin:

250 mg orally twice a day

See the BNF for appropriate use and dosing in specific populations, for example, people with hepatic or renal impairment, in pregnancy and breastfeeding.

For a short explanation of why the committee made this recommendation, see the summary of the evidence on antibiotic prophylaxis for the prevention of recurrent cellulitis and erysipelas.

Full details of the evidence are in the evidence review.

Terms used in the guideline

Ambulatory care

Clinical care that may include diagnosis, observation, treatment and rehabilitation not provided within the traditional hospital bed base or within the traditional outpatient services that can be provided across primary/secondary care.

Cellulitis and erysipelas

Infections of the tissues under the skin (subcutaneous), which usually result from contamination of a break in the skin. Both conditions are characterised by acute localised inflammation and oedema, with lesions more superficial in erysipelas with a well-defined, raised margin (World Health Organization, WHO model prescribing information: drugs used in skin diseases, bacterial infections, staphylococcal and streptococcal infections).

  • National Institute for Health and Care Excellence (NICE)