Table 1.

Streptococcal toxic shock syndrome (STSS) (Streptococcus pyogenes) 2010 CDC case definition⁴

Clinical Criteria	1. Hypotension defined by a systolic blood pressure ≤ 90 mmHg for adults or less than the fifth percentile by age for children aged ≤16 years. 2. Multi-organ involvement characterized by two or more of the following: a. Renal impairment: Creatinine ≥2 mg/dL (≥177 μmol/L) for adults or ≥ twice the upper limit of normal for age. In patients with preexisting renal disease, ˃ twofold elevation over the baseline level. b. Coagulopathy: Platelets ≤100,000/mm3 (≤100 × 106/L) or disseminated intravascular coagulation, defined by prolonged clotting times, low fibrinogen level, and the presence of fibrin degradation products. c. Liver involvement: Alanine aminotransferase, aspartate aminotransferase, or total bilirubin levels ≥twice the upper limit of normal for the patient's age. In patients with preexisting liver disease, a ˃ twofold increase over the baseline level. d. Acute respiratory distress syndrome: defined by acute onset of diffuse pulmonary infiltrates and hypoxemia in the absence of cardiac failure or by evidence of diffuse capillary leak manifested by acute onset of generalized edema, or pleural or peritoneal effusions with hypoalbuminemia. e. Generalized erythematous macular rash: may desquamate. f. Soft-tissue necrosis: including necrotizing fasciitis or myositis, or gangrene.
Laboratory Criteria	Isolation of group A Streptococcus
Probable: A case that meets the clinical case definition in the absence of another identified etiology for the illness and with isolation of group A Streptococcus from a non-sterile site. Confirmed: A case that meets the clinical case definition and with isolation of group A Streptococcus from a normally sterile site (e.g. blood or cerebrospinal fluid or, less commonly, joint, pleural, or pericardial fluid).