A rethink to how we manage uncomplicated cellulitis...

See here.

Essentially, in this study of culture negative cellulitis (without abscess), the authors show that Group A streptococcus is responsible for >75% of cases, and based on response to beta-lactams, 95% of cases are probably caused by GAS, GBS, and MSSA meaning that the need for empiric vancomycin in cellulitis is questioned -- even in areas with high MRSA like the USA.

This CID article discusses how physicians often use too broad a spectrum (i.e. gram negative coverage for non-complicated cellulitis) and utilize too many laboratory and imaging resources.

UPDATE FEB 2011:
The IDSA MRSA guidelines incorporate this data saying initial VANCO is not necessary unless septic shock or purulent cellulitis.  VANCO would be added for those not responding (though you should note erysipelas often worsens in the first 24h of therapy, and  non-cellulitis as a cause of red leg is a common reason for non-improvement)