A new proposed classification for skin and soft tissue infections was partly inspired by an existing classification for diabetic foot infection.1
In the late ‘90s, the FDA proposed a system that categorized skin and soft tissue infections as complicated or uncomplicated. The complicated infections were ones that involved deep structures or required surgical intervention and the uncomplicated infections were superficial. In 2013, the FDA revised this system and it included only three kinds of infection: cellulitis/erysipelas, wound infection, and major cutaneous abscess.
The trouble is that there a lot of other kinds of less severe complications and infections that did not fall under this system, and these recent changes left no way for new kinds of antimicrobials to get approved.
This is the purpose for the change in classification that Lipsky and colleagues proposed in their recent manuscript.1 What they did was to take the International Working Group on the Diabetic Foot’s algorithmic approach and make some very slight modifications based on the existing diabetic foot infection classification by the Infectious Diseases Society of America. This is pretty compatible with previous systems and really requires only a slight adjustment.
The biggest adjustment suggested is dividing the “moderate” infection class into 2a and 2b.1 Infections deemed 2a are local infections that are more horizontally extensive and 2b are infections that are more vertically extensive, expanding below the subcutaneous tissue. I hope this helps the clinician better direct therapy to improve patient outcomes.
1. Lipsky BA, Silverman MH, Joseph WS. A proposed new classification of skin and soft tissue infections modeled on the subset of diabetic foot infection. Open Forum Infect Dis. 2017; 4(1):ofw255.