Smallpox differential diagnosis

In the past, chickenpox was regularly mistaken for smallpox. Pustular scarring that can be seen in the face is a common symptom of both infections. Many times herpes zoster and erythema multiforme produce a vesicular rash and fever that has been confused with smallpox.

Conditions to consider

 * Insect bites


 * Kawasaki diseases


 * Measles


 * Monkeypox


 * Rubella


 * Atypical measles


 * Coxsackievirus


 * Acne


 * Acute leukemia


 * Secondary syphilis


 * Molluscum contagiosum


 * Infectious mononucleosis


 * Toxic erythemas


 * Rat-bite fever


 * Parvovirus B19


 * Cytomegalovirus


 * Scarlet fever


 * Rocky Mountain spotted fever


 * Stevens-Johnson syndrome


 * Syphilis


 * Monkeypox


 * Varicella-zoster virus


 * Drug eruptions


 * Chickenpox

Differential

 * Influenza


 * Meningococcemia


 * Rickettsialpox


 * Poxviruses


 * Meningitis


 * Enteroviruses


 * Herpes zoster


 * Malaria


 * Impetigo