SVS grades 0 (none), 1 (mild), 2 (moderate), and 3 (severe: limb and/or life-threatening)
SVS adaptation of Infectious Diseases Society of America (IDSA) and International Working Group on the Diabetic Foot (IWGDF) perfusion, extent/size, depth/tissue loss, infection, sensation (PEDIS) classifications of diabetic foot infection

SVS Grade: 3

SVS Grade: 0
IDSA/PEDIS infection severity
Uninfected
Clinical manifestation of infection
No symptoms or signs of infection Infection present, as defined by the presence of at least 2 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)
SVS Grade: 1
IDSA/PEDIS infection severity
Mild
Clinical manifestation of infection
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)
SVS Grade: 2
IDSA/PEDIS infection severity
Moderate
Clinical manifestation of infection
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)
SVS Grade: 3
IDSA/PEDIS infection severity
Severe*
Clinical manifestation of infection
Local infection (as described above) with the signs of SIRS, as manifested by two or more of the following: Temperature >38° 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 cu/mm or 10% immature (band) forms

PACO₂, Partial pressure of arterial carbon dioxide; SIRS, systemic inflammatory response syndrome.
*Ischemia may complicate and increase the severity of any infection. Systemic infection may sometimes manifest with other clinical findings, such as hypotension, confusion, vomiting, or evidence of metabolic disturbances, such as acidosis, severe hyperglycemia, new-onset azotemia.
Lipsky BA, Berendt AR, Cornia PB, Pile JC, Peters EJG, Armstrong DG, et al. 2012 IDSA clinical practice guideline for the diagnosis and treatment of diabetic foot infections. Clin Infect Dis 2012;54:e132-73.
Lipsky BA, Berendt AR, Cornia PB, Pile JC, Peters EJG, Armstrong DG, et al. 2012 IDSA clinical practice guideline for the diagnosis and treatment of diabetic foot infections. Clin Infect Dis 2012;54:e132-73.