Pirquet, Clemens, Baron (Freiherr) von


 

b. May 12, 1874, Vienna, Austria
d. Feb. 28, 1929, Vienna
Austrian physician who originated a skin test for tuberculosis that bears his name.
Von Pirquet attended the universities of Vienna, Königsberg, and Graz and graduated from Graz in 1900. He became a professor of pediatrics at Johns Hopkins University in Baltimore in 1908, a position he held for two years before returning to Austria.
In 1906 von Pirquet noticed that patients who had received injections of horse serum or smallpox vaccine usually had quicker, more severe reactions to second injections. He used the word allergy to describe the reactions. While studying the symptoms of cowpox vaccination, he also developed a new theory about the incubation time of infectious diseases and the formation of antibodies.
In Von Pirquet's skin test for tuberculosis, a drop of tuberculin is scratched into the surface of a small area of skin. The development of a red, raised area at the site of application, called Pirquet's reaction, indicates the presence of tuberculosis. In 1909 he published the results of a series of tuberculin tests of inhabitants of Vienna that showed that 70 percent of the children tested had been infected by tuberculosis by the age of 10 and more than 90 percent by the age of 14.