Table 3.4.

Foot infection grading in Wound, Ischemia, and foot Infection (WIfI) classification

Clinical manifestation of infection	SVS	IDSA/PEDIS infection severity
No symptoms or signs of infection	0	Uninfected
Infection present, as defined by the presence of at least two of the following items:  • Local swelling or induration  • Erythema >0.5 to ≤2 cm around the ulcer  • Local tenderness or pain  • Local warmth  • Purulent discharge (thick, opaque to white, or sanguineous secretion)	1	Mild
Local infection involving only the skin and the subcutaneous tissue (without involvement of deeper tissues and without systemic signs as described below). Exclude other causes of an inflammatory response of the skin (eg, trauma, gout, acute Charcot neuro-osteoarthropathy, fracture, thrombosis, venous stasis).
Local infection (as described above) with erythema >2 cm or involving structures deeper than skin and subcutaneous tissues (eg, abscess, osteomyelitis, septic arthritis, fasciitis) and no systemic inflammatory response signs (as described below).	2	Moderate
Local infection (as described above) with the signs of SIRS, as manifested by two or more of the following:  • Temperature >38°C or <36°C  • Heart rate >90 beats/min  • Respiratory rate >20 breaths/min or Paco2 <32 mm Hg  • White blood cell count >12,000 or <4000 cells/mm3 or 10% immature (band) forms	3	Severea

IDSA, Infectious Diseases Society of America; Paco₂, partial pressure of arterial carbon dioxide; PEDIS, perfusion, extent, depth, infection, and sensation; SIRS, systemic inflammatory response syndrome; SVS, Society for Vascular Surgery.

^aIschemia may complicate and increase the severity of any infection. Systemic infection may sometimes be manifested with other clinical findings, such as hypotension, confusion, and vomiting, or evidence of metabolic disturbances, such as acidosis, severe hyperglycemia, and new-onset azotemia.