Skin scarifier owned by Clemens von Pirquet (1874-1929), designed for performing his tuberculin skin test, Europe, c.1900-1912

Clemens von Pirquet (1874-1929) devised a tuberculin skin test in 1907 that was a landmark in the diagnosis and prevention of tuberculosis. Two drops of liquid tuberculin were placed on the skin of the forearm approximately 100 mm apart, scratched and covered with cotton wool. If a red hard raised area appeared on the skin within 24 hours of the test, it showed they had the disease, were naturally immune or had acquired immunity in some way. The von Piquet test was later superseded by the Mantoux test, developed by Charles Mantoux, who worked closely with con Pirquet. In the Mantoux test tuberculin is injected under the skin.

Clemens von Pirquet trained as paediatrician in Austria and is best known for his contributions to immunology, coining the terms allergy and allergen in 1906.