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Notable Notes
May 2017

Al Rhazes and the Beginning of the End of Smallpox

Author Affiliations
  • 1Department of the History of Science, Harvard College, Cambridge, Massachusetts
  • 2Department of Dermatology, College of Physicians & Surgeons, Columbia University, New York, New York
JAMA Dermatol. 2017;153(5):420. doi:10.1001/jamadermatol.2017.0771

The critical first step in the global eradication of smallpox was the concept that a single disease could alter an individual so that he or she became resistant to that disease in the future. It was through empirical observations that the great Persian physician of the medieval Islamic golden age, Abu Bakr Muhammad ibn Zakariyya al-Razi, known to the Western world as Al Rhazes (864-930 ce), developed this fundamental philosophical paradigm shift in man’s understanding of a disease. Medieval medicine was based on clinical observations of the most prominent symptoms of epidemic diseases, particularly diseases with distinctive cutaneous eruptions, such as smallpox, plague, and measles. Rhazes opposed Hippocrates’ and Galen’s concept of the 4 humors. In his landmark “A Treatise on the Small-Pox and Measles,” Rhazes recognized that the 2 were separate diseases.1 Rhazes’ observations and conclusions were important in the genesis of the ontologic concept of disease (ie, distinct, specific disease entities exist, each with its own unique pathogenesis).

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