Rhazes Diagnostic Differentiation of Smallpox and Measles

Background: Abu Bakr Mohammad Ibn Zakariya al-Razi, known in the west as Rhazes, was born in 865 AD in the ancient city of Rey, near Tehran and died in the same town about 925 AD. He was the first person who distinguished the infectious rashes, in particular smallpox, from measles in a masterful demonstration of clinical observations, providing valid guidelines for the sound treatment of both. This study compares Rhazes Diagnostic Differentiation of Smallpox and Measles. Methods: There is an attempt in this study to compare modern microbiology with the chapters of Rhazes’s fi Aljadari wa-al-hasbah. We used this book in its original language (Arabic) along with its Persian and English translations. Results: Rhazes was among the first to recognize the need for sanitation of infected patients in hospitals. Rhazes prepared Al-Jodari Wa Hasbah, the first treatise ever written on smallpox and measles for diagnostic differentiation between these two infections, which is the basis for new medicine to diagnose and treat smallpox and measles, according to his experience of patients in hospital. He also noted that the cause of these infections was the yeast transmitted by the blood route. Today, the cause of smallpox and measles is known to be viruses. Rhazes not only classified the type of infections based on location and the time of the appearance of the symptoms in these two infections, but also he scaled the degree of severity and prognosis of infections according to the color and location of rashes. Conclusion: The method of differential diagnosis of measles and smallpox was precisely described based on his clinical experience and observation in hospitals; it is the best reference in the history of medicine for recognition of these two infections. This article is a review of Rhazes’s views in medicine and their comparison with the modern microbiology.