CHAPTER XIX. 



SCARLET FEVER.— MEASLES. 

 SCAELET FeVEE. 



ScAELET Fevee is a highly contagious disease peculiar to man. It 

 produces inflammation of the tonsils and adjoining parts, fever, and 

 a general punctiform eruption. The period of incubation is about 

 a week, and the rash usually appears on the second day. In some 

 cases the disease manifests itself in an extremely mild form, known 

 as latent scarlet fever, in which there is only a slight febrile attack, 

 or a mild sore throat, with very little or no rash. Many cases 

 would not be recognisable as such if they were not capable of 

 conveying scarlet fever, or unless other cases followed or occurred 

 simultaneously which were undoubtedly typical cases of the disease. 

 The occurrence of such cases in the early history of an epidemic 

 often causes the greatest difficulty in tracing the origin of the 

 outbreak, and indeed in some cases renders it quite impossible to 

 do so. 



The virus is given off by the skin, in desquamation, and possibly 

 by the urine. It maintains its vitality in clothing for months, and 

 sometimes longer. It may also be conveyed by the hands of the 

 physician to women during parturition. The disease may be 

 transferred by subcutaneously inoculating persons, who have not 

 previously contracted scarlet fever, with virus obtained by puncturing 

 the eruption on the skin. 



After death the internal organs appear to the naked eye more or 

 less healthy. The liver is soft, the kidneys are congested, the ileum 

 is inflamed, and Peyer's patches enlarged and congested ; but these 

 conditions are also produced by other causes. There are inflam- 

 matory changes in the lymphatic follicles of the tonsUs, and the 

 larynx and trachea. Other morbid lesions, especially in the kidneys, 

 are associated with the sequelse and complications, and though 

 commonly occurring in scarlet fever are also found in other diseases. 



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