The association between streptococci and scarlet fever was confirmed by Alphonse Dochez and George and Gladys Dick in the early 1900s.Also in 1884, the worlds first convalescent home for people with scarlet fever was opened at Brockley Hill, Stanmore, founded by Mary Wardell.Nil Filatov (in 1895) and Clement Dukes (in 1894) described an exanthematous disease which they thought was a form of rubella, but in 1900, Dukes described it as a separate illness which came to be known as Dukes disease, Filatovs disease, or fourth disease. However, in 1979, Keith Powell identified it as in fact the same illness as the form of scarlet fever which is caused by staphylococcal exotoxin and is known as staphylococcal scalded skin syndrome.Scarlet fever serum from horses blood was used in the treatment of children beginning in 1900 and reduced mortality rates significantly.In 1906, the Austrian pediatrician Clemens von Pirquet postulated that disease-causing immune complexes were responsible for the nephritis that followed scarlet fever.Bacteriophages were discovered in 1915 by Frederick Twort. His work was overlooked and bacteriophages were later rediscovered by Felix dHerelle in 1917. The specific association of scarlet fever with the group A streptococci had to await the development of Lancefields streptococcal grouping scheme in the 1920s. George and Gladys Dick showed that cell-free filtrates could induce the erythematous reaction characteristic of scarlet fever, proving that this reaction was due to a toxin.
It was redescribed by Johann Weyer during an epidemic in lower Germany between 1564 and 1565; he referred to it as scarlatina anginosa. The first unequivocal description of scarlet fever appeared in a book by Joannes Coyttarus of Poitiers, De febre purpura epidemiale et contagiosa libri duo, which was published in 1578 in Paris. Daniel Sennert of Wittenberg described the classical scarlatinal desquamation in 1572 and was also the first to describe the early arthritis, scarlatinal dropsy, and ascites associated with the disease.In 1675 the term that has been commonly used to refer to scarlet fever, "scarlatina", was written by Thomas Sydenham, an English physician. In 1827, Richard Bright was the first to recognize the involvement of the renal system in scarlet fever.The association between streptococci and disease was first described in 1874 by Theodor Billroth, discussing people with skin infections. Billroth also coined the genus name Streptococcus. In 1884 Friedrich Julius Rosenbach edited the name to its current one, Streptococcus pyogenes, after further looking at the bacteria in the skin lesions. The organism was first cultured in 1883 by the German surgeon Friedrich Fehleisen from erysipelas lesions.Also in 1884, the German physician Friedrich Loeffler was the first to show the presence of streptococci in the throats of people with scarlet fever. Because not all people with pharyngeal streptococci developed scarlet fever, these findings remained controversial for some time.