• Fever: temperature 38.9°C (102.0°F) or greater

• Rash: diffuse macular erythroderma

• Desquamation: 1-2 wk after onset, particularly on palms, soles, fingers, and toes

• Hypotension: systolic pressure 90 mm Hg or less for adults; lower than fifth percentile for age for children younger than 16 years of age; orthostatic drop in diastolic pressure of 15 mm Hg or greater from lying to sitting; orthostatic syncope or orthostatic dizziness

• Multisystem organ involvement: 3 or more of the following:

» Gastrointestinal: vomiting or diarrhea at onset of illness

» Muscular: severe myalgia or creatinine phosphokinase concentration greater than twice the upper limit of normal

» Mucous membrane: vaginal, oropharyngeal, or conjunctival hyperemia

» Renal: serum urea nitrogen or serum creatinine concentration greater than twice the upper limit of normal or urinary sediment with 5 white blood cells/high-power field or greater in the absence of urinary tract infection

» Hepatic: total bilirubin, aspartate transaminase, or alanine transaminase concentration greater than twice the upper limit of normal

» Hematologic: platelet count 100 000/mm³or less

» Central nervous system: disorientation or alterations in consciousness without focal neurologic signs when fever and hypotension are absent

• Negative results on the following tests, if obtained:

» Blood, throat, or cerebrospinal fluid cultures; blood culture may be positive for S aureus

» Serologic tests for Rocky Mountain spotted fever, leptospirosis, or measles

• Probable: a case that meets the laboratory criteria and in which 4 of 5 clinical findings are present

• Confirmed: a case that meets laboratory criteria and all 5 of the clinical findings, including desquamation, unless the patient dies before desquamation occurs.