SCARLET FEVER. Synonyms.—Scarlatina; Scarlet Rash. Definition ...

spasms of the pharnyx and larynx, rendering deglutition and
respiration very difficult; great prostration, a stage of paralysis, which
generally terminates in death.
Etiology.—The specific cause has not yet been determined, though
bacteriologists agree that it is microbic in origin, that a toxin is
developed which infects the saliva and blood of the victim. This is
communicated to man in about ninety per cent of all cases by the bite of
a rabid dog.
The presence of saliva, however, on an abraded surface is sufficient to
produce the disease. Of domestic animals liable to rabies, the cat, horse,
and sheep are next in order, while a number of wild animals are
susceptible, and when infected lose their shyness, timid animals
becoming bold.
Many persons seem immune, as only about twelve to fifteen per cent of
the persons bitten contract the disease. The degree of immunity,
however, most likely, is the result of the part bitten. Thus Ballinger
states that ninety per cent of all persons bitten in the face contract
rabies, while only a small per cent are affected when bitten on covered
parts of the body, the virus being wiped off by the intervening clothing.
It is quite rare in the United States, while in Russia it is quite common.
The toxin seems to spend its force upon the central nervous system.
Pathology.—The pathological changes found after death are not
different from those in some other diseases, hence are not characteristic.
Thus we find congestion of the mucous membrane of the pharynx,
larynx, trachea, and bronchi, and sometimes of the lungs.
The abdominal viscera is not affected. The blood-vessels of the cerebrospinal
system are congested, and sometimes minute hemorrhages occur.
These are most marked in the medulla and upper part of the spinal
cord, but may be entirely absent.
Symptoms.—The period of incubation is longer than that of any other
known disease, and varies greatly in different cases, usually a shorter
time in children than in adults. The intensity of the virus and location of
the wound, in all probability, determine to some extent the time of the
forming stage. When the injury is large and on the face or head, the
toxin does its work more quickly.
The Eclectic Practice of Medicine - PART I - Infectious Diseases - Page 246