Cellulitis and erysipelas

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

Last reviewed: 26 Jun 2025

Last updated: 10 Jun 2025

Cellulitis and erysipelas can usually be diagnosed based on history and examination only, although blood cultures and microscopic examination of cutaneous aspirates, biopsies, or swabs should be considered for selected patients, including those who are immunocompromised.

Prior episodes, preexisting lymphedema or venous insufficiency, diabetes, obesity, and tinea pedis can all predispose to cellulitis.

Antibiotics targeted at the most common etiologies (streptococci and Staphylococcus aureus) usually result in resolution.

Definition

Cellulitis is an acute spreading infection of the skin with visually indistinct borders that principally involves the dermis and subcutaneous tissue.[1] It is characterized by erythema, edema, warmth, and tenderness, and most commonly occurs in the legs.

Erysipelas is a distinct form of superficial cellulitis with notable lymphatic involvement and is raised, sharply demarcating it from uninvolved skin.[1][2]

Animal bites (including human bites), surgical wound infections, diabetic foot infections, and cellulitis or erysipelas in children and pregnant women are beyond the scope of this topic. See our topics "Animal bites" and "Diabetic foot infections".

History and exam

Key diagnostic factors

skin discomfort
macular erythema
disruption of cutaneous barrier
raised bright-red erythema with clearly demarcated margins (erysipelas)
risk of infection with MRSA

Full details

Other diagnostic factors

history of diabetes
constitutional prodrome
lymphangitis/regional lymphadenopathy
Identifiable port of entry
history of immunocompromise
unusual exposure (salt or fresh water, bite)

Full details

Risk factors

diabetes
venous insufficiency and chronic leg edema
dermatosis
lymphedema
prior episode of cellulitis
toe web abnormalities
intravenous drug use
overweight
military service

Full details

Diagnostic tests

1st tests to order

CBC
purulent focus culture and molecular diagnostic procedures

Full details

Tests to consider

skin aspiration with culture and molecular diagnostic procedures
blood culture
skin biopsy
plain film x-ray
ultrasound
CT scan
MRI

Full details

Treatment algorithm

ACUTE

mild

moderate

severe

ONGOING

treatment failure

frequent relapses

Contributors

Authors

Arash Mostaghimi, MD, MPA, MPH

Assistant Professor of Dermatology

Harvard Medical School

Director, Inpatient Consultation Service

Department of Dermatology

Brigham and Women’s Hospital

Boston

Disclosures

AM has received fees or honoraria for consulting from hims and hers, AbbVie, Sun Pharma, Pfizer, Digital Diagnostics, Lilly, Equillium, ASLAN, Boehringer Ingelheim, Figure 1, Dermatheory, Olaplex, and Legacy Healthcare.

Acknowledgements

Dr Arash Mostaghimi would like to gratefully acknowledge Dr Matthew C. Robinson, the previous contributor to this topic.

Disclosures

MCR declares that he has no competing interests.

Peer reviewers

Robert W. Bradsher, MD

Ebert Professor of Medicine

Director

Division of Infectious Diseases

University of Arkansas for Medical Sciences

Little Rock

Disclosures

RWB declares that he has no competing interests.

Jorg Ruhe, MD, MPH

Assistant Attending

Beth Israel Medical Center

New York

Disclosures

JR declares that he has no competing interests.

References

Our in-house evidence and editorial teams collaborate with international expert contributors and peer reviewers to ensure that we provide access to the most clinically relevant information possible.

Key articles

Raff AB, Kroshinsky D. Cellulitis: a review. JAMA. 2016 Jul 19;316(3):325-37. Abstract

Stevens DL, Bisno AL, Chambers HF, et al. Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America. Clin Infect Dis. 2014 Jul 15;59(2):e10-52.Full text Abstract

American College of Radiology. ACR appropriateness criteria: suspected osteomyelitis, septic arthritis, or soft tissue infection (excluding spine and diabetic foot). 2022 [internet publication].Full text

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

Differentials
- Necrotizing fasciitis
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Guidelines
- 2018 WSES/SIS-E consensus conference: recommendations for the management of skin and soft-tissue infections
- Practice guidelines for the diagnosis and management of skin and soft tissue infections
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Patient information
Cellulitis and erysipelas
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Videos
Venepuncture and phlebotomy: animated demonstration
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Cellulitis and erysipelas

Summary

Definition

History and exam

Key diagnostic factors

Other diagnostic factors

Risk factors

Diagnostic tests

1st tests to order

Tests to consider

Treatment algorithm

mild

moderate

severe

treatment failure

frequent relapses

Contributors

Authors

Arash Mostaghimi, MD, MPA, MPH

Disclosures

Acknowledgements

Disclosures

Peer reviewers

Robert W. Bradsher, MD

Disclosures

Jorg Ruhe, MD, MPH

Disclosures

References

Key articles

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

Differentials

Guidelines

Patient information

Videos

Log in or subscribe to access all of BMJ Best Practice

Log in or subscribe to access all of BMJ Best Practice

Log in to access all of BMJ Best Practice