Continuing medical educationLower limb cellulitis and its mimics: Part I. Lower limb cellulitis
Section snippets
Definitions
Key points Clinicians should use the term “cellulitis” for superficial spreading skin infections without an underlying collection of pus The term “erysipelas” has been used in 3 different ways
Cellulitis is a superficial, diffuse, spreading infection of the skin. In the most clinically useful nomenclature, the term “cellulitis” does not refer to cutaneous inflammation associated with collections of pus, such as septic bursitis, furuncles, or cutaneous abscesses. In those situations, when redness, heat,
Predisposing factors
Key points Lower limb cellulitis occurs with about equal frequency in men and women and is more common with advancing age One attack of lower limb cellulitis predisposes to future episodes, with an annual recurrence rate of about 8% to 20%
Whether it is called erysipelas or cellulitis, this infection involves the lower extremities in about 70% to 80% of cases, as reported in large series, mostly of hospitalized patients.1, 2, 3, 4, 5, 6, 7 Its overall frequency is approximately 199 per 100,000 person-years,
Pathogenesis and pathology
Key points The organisms causing lower limb cellulitis typically enter the skin through defects in the cutaneous surface, particularly in the presence of edema, venous insufficiency, obesity, trauma, ulceration, or dermatologic disorders The reservoir for these infecting organisms is often the interdigital toe spaces, especially when maceration, scaling, and fissuring are present
Except for rarely being caused by bacteremia from another site of infection, cellulitis occurs from microbes entering the skin
Clinical features
Key points Although fever and systemic symptoms may be prominent in many patients, about 30% to 80% of patients with lower limb cellulitis are afebrile The major dermatologic features of cellulitis are redness, edema, pain, and warmth in the affected skin, often accompanied by cutaneous hemorrhage
The systemic features of infection can be prominent in patients with cellulitis and occasionally precede any signs of cutaneous inflammation by many hours.1 The mechanism is uncertain but may represent a vigorous
Diagnosis
Key points The white blood cell count, erythrocyte sedimentation rate, and C-reactive protein levels are commonly elevated, but normal values of these tests do not exclude the diagnosis of cellulitis Evidence from cultures, aspirates, biopsy specimens, and serologic studies implicate streptococci of various groups in about 75% to 90% of cases; Staphylococcus aureus (almost always methicillin-susceptible) is evident in 10% of cases
The white blood cell count is elevated in about 35% to 50% of patients,1, 7,
Treatment
Key points Most patients do not require hospitalization, and a 5-day regimen of oral antimicrobials effective against streptococci and methicillin-susceptible Staphylococcus aureus, such as dicloxacillin or cephalexin, should usually suffice A brief course of oral corticosteroids significantly shortens the duration of illness and may reduce the frequency of subsequent episodes
As indicated above, most patients respond well to penicillin, and oral therapy is equivalent to parenteral administration in
Unusual causes of lower limb cellulitis
Key point Clinicians should suspect unusual organisms as the causes of cellulitis in immunocompromised hosts and in patients with chronic liver disease, animal bites, immersion in salt or fresh water, and penetrating trauma
Conclusion
Cellulitis of the lower limbs is a superficial spreading infection primarily caused by streptococci of various groups, less commonly by S aureus, and occasionally by other microbes. Infection with MRSA is rare. Treatment of cases of typical lower limb cellulitis includes antibiotics active against streptococci and S aureus, leg elevation, and systemic corticosteroids. Clinicians should treat any underlying or predisposing dermatologic conditions, such as venous eczema, and especially
References (111)
- et al.
Erysipelas and cellulitis: clinical and microbiological spectrum in an Italian tertiary care hospital
J Infect
(2005) - et al.
Incidence of lower-extremity cellulitis: a population-based study in Olmsted County, Minnesota
Mayo Clin Proc
(2007) - et al.
Factors predisposing to acute and recurrent bacterial non-necrotizing cellulitis in hospitalized patients: a prospective case-control study
Clin Microbiol Infect
(2010) - et al.
Risk factors for recurrent lower extremity cellulitis in a U.S. Veterans Medical Center population
Am J Med Sci
(2006) - et al.
Recurrent acute leg cellulitis in patients after radical vulvectomy
Gynecol Oncol
(1988) - et al.
Cellulitis: evaluation of possible predisposing factors in hospitalized patients
Diag Microbiol Infect Dis
(1999) - et al.
Bullous erysipelas: a retrospective study of 26 patients
J Am Acad Dermatol
(1999) - et al.
Efficacy of oral β-lactam versus non-β-lactam treatment of uncomplicated cellulitis
Am J Med
(2008) - et al.
Comparison of initial antibiotic choice and treatment of cellulitis in the pre- and post-community-acquired methicillin-resistant Staphylococcus aureus eras
Am J Emerg Med
(2009) - et al.
Long-term antimicrobial therapy in the prevention of recurrent soft-tissue infections
J Infect
(1991)
Bacteremic cellulitis caused by non-01, non-0139 Vibrio cholerae: report of a case in a patient with hemochromatosis
Diag Microbiol Infect Dis
Gram-negative cellulitis complicating cirrhosis
Mayo Clin Proc
Serratia cellulitis and secondary infection of leg ulcers by Serratia
J Am Acad Dermatol
Bullous cellulitis caused by Serratia marcescens
Int J Infect Dis
Erysipelas: clinical and bacteriologic spectrum and serological aspects
Clin Infect Dis
The role of β-hemolytic streptococci in causing diffuse, nonculturable cellulitis: a prospective investigation
Medicine (Baltimore)
Epidemiological, bacteriological and complicating features of erysipelas
Scand J Infect Dis
Antibiotic and prednisolone therapy of erysipelas: a randomized, double blind, placebo-controlled study
Scand J Infect Dis
Randomised controlled trial of intravenous antibiotic treatment for cellulitis at home compared with hospital
BMJ
Factors associated with complications and mortality in adult patients hospitalized for infectious cellulitis
Eur J Microbiol Infect Dis
Risk factors for acute cellulitis of the lower limb: a prospective case-control study
Clin Infect Dis
Risk factors for erysipelas of the leg (cellulitis): case control study
BMJ
Chronic dermatomycoses of the foot as risk factors for acute bacterial cellulitis of the leg: a case-control study
Dermatology
Risk factors for erysipelas of the leg in Tunisia: a multicenter case-control study
Dermatology
Incidence of erysipelas following venectomy for coronary artery bypass surgery
Infection
Manifestations of cellulitis after saphenous venectomy for coronary artery bypass surgery
J Eur Acad Dermatol Venereol
Recurrent cellulitis after coronary artery bypass surgery. Association with superficial fungal infection in saphenous venectomy limbs
JAMA
Vein-donor-leg cellulitis after coronary artery bypass surgery
Ann Intern Med
Relapse of erysipelas following treatment with prednisolone or placebo in addition to antibiotics: a 1-year follow-up
Scand J Infect Dis
Recurrent erysipelas: predisposing factors and costs of prophylaxis
Infection
A predictive model of recurrent lower extremity cellulitis in a population-based cohort
Arch Intern Med
Oedema as a risk factor for multiple episodes of cellulitis/erysipelas of the lower leg: a series with community follow-up
Br J Dermatol
Recurrent erysipelas: risk factors
J Dtsch Dermatol Ges
Recurrent erysipelas: 47 cases
Dermatology
Erysipelas as a sign of subclinical primary lymphoedema: a prospective quantitative scintigraphic study of 40 patients with unilateral erysipelas of the leg
Br J Dermatol
Lymphatic abnormalities demonstrated by lymphoscintigraphy after lower limb cellulitis
Br J Dermatol
Quantitative cultures of biopsy specimens from cutaneous cellulitis
Arch Intern Med
Lymphoscintigraphic evaluation in patients after erysipelas
Lymphology
Association of athlete’s foot with cellulitis of the lower extremities: diagnostic value of bacterial cultures of ipsilateral interdigital space samples
Clin Infect Dis
Anal colonization of group G beta-hemolytic streptococci in relapsing erysipelas of the lower extremity
Clin Infect Dis
Recurrent acute leg cellulitis after hysterectomy with pelvic lymphadenectomy
Br J Obstet Gynaecol
Recurrent postcoital lower-extremity streptococcal erythroderma in women. Streptococcal-sex syndrome
JAMA
Recurrent erysipelas caused by group B streptococcus organisms
Arch Dermatol
Acute bacterial, nonnecrotizing cellulitis in Finland: microbiological findings
Clin Infect Dis
Erysipelas
Int J Dermatol
Microbiologic evaluation of cutaneous cellulitis in adults
Arch Intern Med
Treatment of cellulitis with ceforanide
Antimicrob Agents Chemother
Streptococcal cause of erysipelas and cellulitis in adults. A microbiologic study using a direct immunofluorescence technique
Arch Dermatol
Clinical practice guidelines by the Infectious Diseases Society of America for the treatment of methicillin-resistant Staphylococcus aureus infections in adults and children
Clin Infect Dis
Cited by (76)
Bacterial Skin and Soft Tissue Infections in Older Adults
2024, Clinics in Geriatric MedicineCellulitis: A Review of Pathogenesis, Diagnosis, and Management
2021, Medical Clinics of North AmericaDistinguishing Cellulitis from Its Noninfectious Mimics: Approach to the Red Leg
2021, Infectious Disease Clinics of North AmericaCitation Excerpt :About 30% to 80% of patients with lower-limb cellulitis are afebrile.6 Leukocytosis and elevated inflammatory markers (eg, erythrocyte sedimentation rate [ESR], C-reactive protein [CRP]) may suggest a diagnosis of cellulitis, although they are also not reliable diagnostic criteria, as they occur in only 35% to 50% and 60% to 95% of patients, respectively; therefore, their absence is less helpful in ruling out cellulitis.6 Clinical decision-making tools to improve the diagnosis of cellulitis are being developed based on small preliminary studies, including the ALT-70 and NEW HAvUN scores.
Bacterial acute non necrosing cellulitis (erysipelas) in adult
2021, Revue de Medecine InterneMost prevalent infectious skin disease
2020, FMC Formacion Medica Continuada en Atencion Primaria
Funding sources: None.