It is apparently becoming very much milder in the United States than it was a few years ago. It is still, however, sufficiently serious to require that cases be quarantined and put under careful medical supervision.
Scarlet fever is not nearly so contagious as measles in that the incubation period is very short and the quarantine period is very long, and that it can be carried by fomites (intermediary persons or objects).
The most frequent cause of scarlet fever contagion is direct contagion from a person who has the disease to another. However, milk epidemics have been reported. In Massachusetts, between 1909 and 1914, 845 cases of scarlet fever were traced to milk, and in Chicago the health commissioner found 245 cases on one single milk route. Pasteurization of the milk prevents it from carrying scarlet fever. The milk which causes scarlet fever is always contaminated by human hands or contact. Cows do not have the disease in any form.
The incubation period is often as short as one day. That is to say, the time which elapses between exposure and the eruption is only about 48 hours. Nearly all cases have the eruption within two or three days of the exposure.
In handling a case of scarlet fever in the home, the room should be prepared beforehand for a long siege, as the quarantine period should be from four to six weeks. Few health departments permit quarantine to be broken in less than 28 days after scarlet fever.
After a case of scarlet fever has been cared for in a room, the room should be fumigated, all the objects which the patient has touched, such as books and toys, should be burned, the bedclothes and personal linen should be thoroughly disinfected, and the walls either thoroughly washed or, more properly, washed and repapered and repainted.
The treatment of scarlet fever has been fairly satisfactory with a serum, and an attempt has been made to prevent cases of scarlet fever with a substance similar to the substance used for the prevention of diphtheria. This, however, has not proved as successful as was at first hoped, and cannot be recommended.
The complications of scarlet fever are particularly treacherous and should be kept in mind by anyone nursing a case. Of these, perhaps the most serious is the effect on the kidneys. This often shows by the passing of dark or bloody urine of small quantity. The diet should be restricted during scarlet fever and this restriction should be conscientiously maintained for the very important reason of its protective effect on the kidneys.
The other complication of scarlet fever is infection of the middle ear. This is usually shown by a rise in temperature, pain and restlessness, and throbbing in the ear. It usually subsides under proper treatment, which consists in opening the drum and letting the pus out at the proper time.