INTRO    EQUATIONS    CRITERIA    DECISION    CONVERT    SPECIALTIES    REFS    SEARCH    NEW    FHIR APP    API    POLICIES    CONTACT

 

Smallpox Risk Assessment (CDC 2025)

 

	*** MODERATE RISK of SMALLPOX: 1 Prodrome Major Criteria and 1 Other Major Criteria and 0 Minor Criteria
	*** MODERATE RISK of SMALLPOX: 1 Prodrome Major Criteria and 0 Other Major Criteria and 4 Minor Criteria
	*** HIGH RISK of SMALLPOX: 1 Prodrome Major Criteria and 2 Other Major Criteria and 0 Minor Criteria
Prodrome Major Criteria
		Febrile prodrome: Fever of ≥101 degreesF, 1 to 4 days prior to rash onset with at least prostration, headache, backache, chills, vomiting or severe abdominal pain
Other Major Criteria
		Classic smallpox lesions: Deep-seated, firm/hard, round well-circumscribed vesicles or pustules; lesions may umbilicate or become confluent
		Lesions in same stage of development: On any one part of the body all lesions in same stage of development
Minor Criteria
		Centrifugal distribution of lesions
		First lesions on the oral mucosalpalate, face, or forearms
		Patient appears toxic or moribund
		Slow evolution of lesions from macule, to papule, to vesicle (1-2 days each stage)
		Lesions on the palms and soles

 

 

 

 

Data action

 

     
 
Include literature references: Yes   No

Notes

• For HIGH-RISK cases:
  • Obtain Infectious Disease and/or Dermatology consultation and alert local and state public health departments immediately.
  • The Response team from the local and/or state public health department will advise on management and specimen collection.
  • Perform Variola testing at Variola testing laboratory and at CDC
  • If variola testing rules out smallpox, continue other diagnostic testing. Patient’s risk of smallpox is low.
  • If variola is positive, then smallpox is confirmed.
• For MODERATE-RISK cases:
  • Obtain Infectious Disease and/or Dermatology consultation.
  • Test for Varicella and other conditions as indicated.
  • If tests confirm a non-smallpox diagnosis, report results to infection control. The patient’s risk of smallpox is low.
  • If no diagnosis is made after tests are completed, ensure specimen adequacy and re-evaluate the patient. At this point, the patient’s risk of smallpox is moderate.
  • If re-evaluation does not reveal a diagnosis, you CANNOT rule out smallpox. Patient’s risk of smallpox is HIGH.

 

References

1. Centers for Disease Control. Evaluating Patients for Smallpox: Acute, Generalized Vesicular or Pustular Rash Illness Protocol. http://www.cdc.gov/smallpox. accessed 12/24/2025.

 

Associated ICD10-CM Codes
 

	B03	Smallpox
	Z20.89	Contact with and (suspected) exposure to other communicable diseases
	Z11.59	Encounter for screening for other viral diseases

 

Associated ICD9-CM Codes
 

	E949.9	Adv eff smallpox vaccine
	V73.1	Screening for smallpox
	V01.3	Smallpox contact
	050.9	Smallpox nos