Cellulitis and erysipelas

Last reviewed: 26 Aug 2023
Last updated: 27 Sep 2022



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
More key diagnostic factors

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)
Other diagnostic factors

Risk factors

  • prior episode of cellulitis
  • diabetes
  • ulcer/wound
  • dermatosis
  • tinea pedis interdigitalis
  • lymphedema
  • venous insufficiency/chronic leg edema
  • overweight
More risk factors

Diagnostic investigations

1st investigations to order

  • CBC
  • purulent focus culture and molecular diagnostic procedures
More 1st investigations to order

Investigations to consider

  • skin aspiration with culture and molecular diagnostic procedures
  • blood culture
  • skin biopsy
  • plain film x-ray
  • ultrasound
  • CT scan
  • MRI
More investigations to consider

Treatment algorithm






treatment failure

frequent relapses



Arash Mostaghimi, MD, MPA, MPH

Assistant Professor of Dermatology

Harvard Medical School

Director, Inpatient Consultation Service

Department of Dermatology

Brigham and Women’s Hospital




AM declares no competing interests relating to work on skin and soft tissue infections. AM has received consulting fees (Pfizer, Hims, Digital Diagnostics, Concert, Lilly, and Abbvie) relating to alopecia research. AM has received equity (Hims), licensing/royalty fees (Pfizer, Concert) for alopecia associated products; clinical trials support (Lilly, Concert). AM is on a medical advisory board (Hims) and is associate editor JAMA Dermatology.


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


MCR declares that he has no competing interests.

Peer reviewers

Robert W. Bradsher, MD

Ebert Professor of Medicine


Division of Infectious Diseases

University of Arkansas for Medical Sciences

Little Rock



RWB declares that he has no competing interests.

Jorg Ruhe, MD, MPH

Assistant Attending

Beth Israel Medical Center

New York



JR declares that he has no competing interests.

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