SCARLET FEVER or SCARLATINA, names applied in differently to an acute infectious disease, characterized by high fever, accompanied with sore throat and a diffuse red rash upon the skin. This fever appears to have been first accurately described by Sydenham in 1676, before which period it had evidently been confounded with smallpox and measles. It is generally believed that the disease is caused by haemolytic streptococci. Klein in 1885 isolated a streptococcus which he termed the streptococcus scarlatinae. The scarlatinal throat is the chief habitat of the or ganism, though it has been found both by Klein and other observ ers in the discharges from the ears of scarlet fever patients.
Mervyn Gordon also isolated from cases the streptococcus con glomerulatus. It is possible that septic cases of scarlet fever are the result of a mixed infection. The serum of patients has been found to contain agglutins to streptococci from cases of erysipelas, septi caemia and puerperal fever, as well as to the streptococci scarla tinae. F. B. Mallory in 1904 published his discovery of "proto zoonlike" bodies in the cells of the epidermis. Other observers have found them in the skin of fatal cases, but failed to find them in the living. The contagion of scarlet fever takes place from a previous case either by the skin during the early stages of the disease or by the nasal or aural discharges of a patient. It may be conveyed by any article of clothing or furniture or by any person that has been in contact with a scarlet fever patient. Infectivity may also take place through a contaminated milk supply, as in the Marylebone epidemic, 1885. Klein here found a disorder in cows which he considered analogous to scarlatina and communicable to man.
The period of incubation in scarlet fever may be as short as one or two days, but in most instances it is probably less than a week. The invasion of this fever is generally sudden, consisting in rigors, vomiting and sore throat, together with a rapid rise of tempera ture and increase in the pulse. About twenty-four hours later the characteristic eruption appears. It is first seen on the neck, chest, arms and hands, but quickly spreads all over the body, al though it is not distinctly marked on the face. This rash consists
of minute thickly-set red spots, which coalesce to form a general diffuse redness, in appearance not unlike that produced by the application of mustard to the skin. In ordinary cases the rash takes about two days to come out, then begins to fade, and by the end of a week from its first appearance it is usually gone.
The severity of a case is in some degree measured by the copi ousness and brilliancy of the rash, except in the malignant varie ties, where there may be little or no eruption. The tongue, which at first was furred, becomes about the fourth or fifth day denuded of its epithelium and acquires the peculiar "strawberry" appear ance characteristic of this fever. The interior of the throat is red and swollen, especially the uvula, soft palate and tonsils, and much secretion exudes from the inflamed surface. There is also tender ness and slight swelling of the glands under the jaw. In favour able cases the fever departs with the disappearance of the erup tion and convalescence sets in with peeling of the cuticle, which first shows itself about the neck, and proceeds slowly over the entire body. Where the skin is thin the desquamation is in the form of fine branny scales ; but where it is thicker, as about the hands and feet, it comes off in large pieces, which sometimes as sume the form of casts of the fingers or toes. The duration of this process is variable, but it is rarely complete before the end of six or eight weeks, and not unfrequently goes on for several weeks beyond that period. It is during this stage that complications are apt to appear.
Scarlet fever shows itself in certain well-marked varieties, of which the following are the chief:— I. Scarlatina Simplex is the most common form; the symp toms are moderate, and the case usually runs a favourable course. In some instances evidences of the disease are so slight that they escape observation and only become known by the patient in fecting another person or subsequently suffering from some of the complications associated with it.