Smallpox: The Course of the Disease

Posted by on Feb 7, 2014

Red Rash Rising

  • The rash first appeared as tiny red flecks that rose into bumps.
  • They seemed to flow from the face downwards, becoming thickest on the face and extremities.
  • This stage lasted about 3 days.


  • The bumps became blisters said to feel like BB pellets under the skin.

Pustules (or “Pocks”)

  • The blisters enlarged and filled with thick yellow pus:

  • At the center of each pustule was a small depression like a bellybutton:

  • In the most common form of the disease, called “discrete” or “distinct” smallpox, the pustules remained separate: patches of normal skin were still visible between them:

  • As their bodies began reabsorbing all that pus, many victims experienced a second high fever; this was generally the most lethal stage of the disease.


  • About 10 days after the rash first appeared, the pustules began to crust and scab over:

  • About two weeks after the rash appeared, the scabs began to fall off, leaving marks that became deep pitted scars, said to be as rough as “nutmeg grater.”
  • At first, the scars were brown on light-skinned people, and pale or white on dark-skinned people. The color faded with time, but the pits did not.
  • A victim remained contagious until every last scab was gone.



This page details the most common form of the disease, once known as “Discrete” or “Distinct” smallpox. Other forms were rarer, but also more lethal:

All photos on this page by J. B. Byles, from Thomas Francis Ricketts, The Diagnosis of Smallpox (London & New York: Cassell and Co., 1908).

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