Management of Leg Cellulitis

Management of Lower Extremity Cellulitis

September 2004

From HealthPartners Medical Group & ClinicsDepartment of Infectious Diseases

Management of Lower Extremity Cellulitis

Cellulitis is defined as an acute, spreading pyogenic inflammation of the dermis and subcutaneous tissue, usually complicating a wound, ulcer, or dermatosis. Cellulitis often involves the lower leg and is commonly accompanied by fever, pain/tenderness, warmth, erythema, and swelling. A recent New England Journal of Medicine article makes the following suggestions regarding the management of uncomplicated lower leg cellulitis.

Common predisposing factors include
- edema
- prior saphenous vein harvesting (such as for coronary artery bypass grafting), and
- fissuring in the toe webs or plantar skin cracking due to a fungal dematosis.
*lymphedema

The most common bacterial causes are

- Group A or
- non-group A beta hemolytic streptococcus and Staphylococcus aureus.

Tissue cultures (needle aspirate or punch biopsy) are usually not indicated in routine care.

Blood cultures are unlikely to be cost-effective as bacteremia is uncommon in cellulitis. Blood cultures might be considered in patients with chills and high fever.

Antibiotic treatment usually consists of a beta-lactam antibiotic with activity against penicillinase-producing S. aureus.

Examples of appropriate oral antibiotics include

a) cephalexin 500 mg every 6 hours,
b) dicloxacillin 500 mg every 6 hours, or
c) clindamycin 300 mg every 6 hours (in penicillin allergic patients).

Examples of appropriate parenteral antibiotics include

- cefazolin 1 g IV every 6 hours,
- ceftriaxone 1 g IV every 24 hours, or
- cefazolin 2 g intravenously once daily plus probenecid 1 g orally once daily (reported to be as effective as once daily ceftriaxone).

Vancomycin or linezolid may be necessary if methicillin-resistant S. aureus is suspected or if the patient is highly allergic to penicillin.

Hospitalization should be considered if the lesion is rapidly spreading, if the systemic response is prominent (i.e., chills and fever >100.5 degrees F), or if there are clinically significant comorbidities such as immunocompromise, neutropenia, asplenia, preexisting edema, cirrhosis, cardiac failure, or renal insufficiency.

Recurrences may be prevented by the use of support stockings to reduce edema, good skin hygiene, and prompt (or prophylactic) treatment of interdigital dermatophytic infections/tinea pedis.

Daily prophylaxis with penicillin G or amoxicillin or erythromycin 250 mg twice daily long-term may help prevent recurrences in individuals who have experienced two or more episodes of cellulitis at the same site.

ReferencesSwartz MN. Cellulitis. NEJM 2004; 350: 904-912.If you have questions relating to this Pearl of the Month, please email your questions to IME Pearl .

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Additional Risk Factors for Leg Lymphedema

Age. As you age, your circulatory system becomes less effective at delivering blood — with its infection-fighting white blood cells — to some areas of your body. As a result, skin abrasions may lead to infections such as cellulitis where your circulation is poor.

Weakened immune system. Illnesses that result in a weakening of your immune system leave you more susceptible to infections such as cellulitis. Examples of these illnesses include chronic lymphocytic leukemia and HIV infection. Taking immune-suppressing drugs, such as prednisone or cyclosporine, also can leave you vulnerable to infections. Immune-suppressing drugs are used to treat a variety of illnesses and to help prevent rejection in people who receive organ transplants.

Diabetes. Having diabetes not only increases your blood sugar but also impairs your immune system and increases your risk of infections. Your skin is one of the many areas of your body that becomes more susceptible to infection. Diabetes may also lead to chronic ulcers of your feet. These ulcers can serve as portals of entry for bacterial infections.

Chickenpox and shingles. These common viral diseases typically cause broken blisters on the skin that can serve as potential entry points for bacterial invasion and infection.

Chronic swelling of your arms or legs (lymphedema). Swollen tissue may crack, leaving your skin vulnerable to bacterial infection.

Complications from Leg Cellulitis

Tissue death (gangrene)
Sepsis, generalized infection and shock
Meningitis (if cellulitis is on the face)
Lymphangitis (inflammation of the lymph vessels)
Bacteremia
Gangrene - tissue death