Smallpox (Variola Major)

Etiology 

• Variola virus -  DNA virus from the genus Orthopoxvirus.
  
• Variola Major associated with 30% mortality
• Variola Minor associated with 1% mortality 

Clinical Findings

• Variola virus is inhaled then over the next 1-2 weeks it replicates in the lymph nodes, bone marrow, and spleen.
• Secondary viremia results high fever, headache, and backaches
  
• Macular to papular to pustular rash progression
  

• begins near mouth, spreads to face, then rapidly to arms and legs, and then hands and feet. Entire body is usually involved within 24 hours
• affects palms and soles (unlike chickenpox)
• uniform rash - all lesions are in similar stages of development 

Diagnosis

• Clinical diagnosis
  
• Send pustular to fluid to lab for...
• Electron microscopy
• Antigen detection
• Polymerase chain reaction

Management

• No specific therapy for smallpox other than supportive care
  
• Respiratory and contact isolation
  
• Immunization if in early stage of disease
  

Review 

• See my video on vesicular  rashes below for a quick review