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NOTE: A surveillance case definition is a set of uniform criteria used to define a disease for public health surveillance. Surveillance case definitions enable public health officials to classify and count cases consistently across reporting jurisdictions. Surveillance case definitions are not intended to be used by healthcare providers for making a clinical diagnosis or determining how to meet an individual patient’s health needs.

Clinical Criteria

An illness with the following clinical manifestations:

  • Fever: temperature greater than or equal to 38.9°C (102.0°F)
  • Rash: diffuse macular erythroderma
  • Desquamation: 1-2 weeks after onset of illness, particularly on the palms and soles
  • Hypotension: systolic blood pressure less than or equal to 90 mm Hg for adults or less than fifth percentile by age for children aged less than 16 years; orthostatic drop in diastolic blood pressure greater than or equal to 15 mm Hg from lying to sitting, orthostatic syncope, or orthostatic dizziness
  • Multisystem involvement (three or more of the following):
    • Gastrointestinal: vomiting or diarrhea at onset of illness
    • Muscular: severe myalgia or creatine phosphokinase level at least twice the upper limit of normal
    • Mucous membrane: vaginal, oropharyngeal, or conjunctival hyperemia
    • Renal: blood urea nitrogen or creatinine at least twice the upper limit of normal for laboratory or urinary sediment with pyuria (greater than or equal to 5 leukocytes per high-power field) in the absence of urinary tract infection
    • Hepatic: total bilirubin, serum glutamic-oxaloacetic transaminase (SGOT), or serum glutamic-pyruvic transaminase (SGPT) at least twice the upper limit of normal for laboratory
    • Hematologic: platelets less than 100,000/mm3
    • 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 Staphylococcus aureus)
    • Rise in titer to Rocky Mountain spotted fever, leptospirosis, or measles

Case Classification


A case with five of the six clinical findings described above


A case with all six of the clinical findings described above, including desquamation, unless the patient dies before desquamation could occur

Related Case Definition(s)