Cephalexin in Cellulitis Treatment

Pathogen Considerations

Typical cellulitis without purulent drainage is primarily caused by beta-hemolytic streptococci, for which beta-lactams like cephalexin provide optimal coverage 1, 2
MRSA is an unusual cause of typical cellulitis, with studies showing that beta-lactam therapy is successful in 96% of cellulitis cases 2
Clindamycin should be reserved for specific scenarios such as beta-lactam allergies or when MRSA coverage is indicated 3, 4

First-line treatment for non-purulent cellulitis is cephalexin 500mg four times daily for 5-10 days 1, 2
Beta-lactam monotherapy is recommended as MRSA is an uncommon cause 2
Clinical improvement should be evident within 5 days; if achieved, a 5-day course is as effective as 10 days 1
Consider empiric MRSA coverage with clindamycin 300-450mg three times daily for purulent cellulitis or failed beta-lactam therapy 3, 4
Clindamycin provides coverage for both streptococci and MRSA in a single agent 4

For patients with beta-lactam allergies, clindamycin is an appropriate alternative 3, 4
For facial cellulitis that fails to respond to clindamycin, consider alternative agents like linezolid or vancomycin due to the risk of complications from proximity to vital structures 5

Unnecessarily prescribing MRSA coverage for typical non-purulent cellulitis 2
Failure to address predisposing conditions such as tinea pedis, venous insufficiency, or lymphedema 1
Not elevating the affected area, which helps promote gravity drainage of edema and inflammatory substances 2