An acute infectious disease, smallpox, or variola, is now uncommon in civilized countries, though from time to time limited epidemics break out in different parts of the world. In the 18th century alone, smallpox killed sixty million human beings, but toward the end of the century Edward Jenner discovered the preventive treatment. The infective agent would appear to be either a minute bacterium or a protozoal organism, and this occurs abundantly in the pustules and crusts which form in this disease. The infection is disseminated through the air, and may be carried for long distances.
The incubation period is about twelve days, and then there is a sudden rise of pain in the back, and often vomiting. On the second day there is often what is called a prodromal rash, and this commonly takes the form of reddening or erythema, a common site being the lower part of the abdomen. On the third day the rash proper makes its appearance in the form of red spots, usually on the forehead and wrists. These spots become elevated, forming papules, and the rash extends to other parts of the body.
When the rash comes out, the fever is reduced, perhaps disappearing altogether. The rash is most profuse, as a rule, on the face and forearms, the trunk being relatively free, and this contrasts strongly with the rash of chicken pox, in which the trunk is particularly affected, while the limbs exhibit very little. Parts subjected to irritation are more likely to display the smallpox rash.
Progressive changes in the rash:
On the sixth day the papules become converted into vesicles, or blisters, containing a fairly clear liquid. The vesicles are depressed in the center. About the eighth day the contents of the vesicles become purulent, that is, the vesicles become pustules, and, from absorption of poisonous matter from them, there is again a rise of temperature, called secondary fever.
A red zone surrounds each pustule, and there is considerable swelling of the neighboring skin, particularly on the face. There is often also intense irritation. The temperature may be very high, and there may be much depression, the patient possibly developing the typhoid state.
On the eleventh day the pustules mature, as it is called; they rupture, and their contents dry, forming blackish scabs, which gradually fall off, leaving more or less pitting. This goes on during the third week, and the temperature also generally falls by lysis.
When the pustules are relatively few and are isolated, the rash is said to be discrete; when they are numerous, and so run together, it is said to be confluent, and then the general symptoms are correspondingly severe. When the disease occurs in a person who has been vaccinated, there may be only a pustule here and there. This is sometimes called the varioloid type of the disease.
In what is called the hemorrhagic type, bleeding occurs into the skin and from mucous membranes, that is, from the nose, the bladder and so on, and the outlook is extremely grave.
The rash always occurs in the mouth, and may invade the larynx, so that there may be considerable swelling of the tongue, and laryngitis. Bronco-pneumonia is a common complication. Conjunctivitis, or perhaps even deeper inflammation of the eyes, may occur, and may result in permanent blindness. Inflammation of the middle ear is not uncommon, and there are other possible complications.
One attack of the disease usually protects against further attack, though second attacks do occur. Efficient Jennerian vaccination almost always gives protection, but this diminishes in the course of years, and re-vaccination should be done at the age of ten and again in adult life. Any person who has possibly been in contact with a person suffering from the disease should be re-vaccinated, unless there has been a successful re-vaccination during the previous five years. Vaccination may even protect when it is done during the early days of the incubation period, and in any case is likely to mitigate the disease, should it develop.
Measures to avoid pitting:
The general treatment of smallpox is that of an infectious disease (q.v.). Isolation must be very strict. In order to lessen the ravages of the disease on the skin, unremitting and careful attention is required in sponging and the application of antiseptic and sedative ointments. Sometimes red curtains and red shades for artificial lights are used in order to protect the skin from the chemical rays of light, and thereby lessen the irritation on the skin of the face and the subsequent pitting. This may be of some use, but the flood red light is apt to have a depressing effect on the patient. See: Chicken-pox.,
Application and treatment:
As in all infectious disease, it is essential to get a proper diagnosis, and the disease must be caught and arrested in the early stages, due to the toxic side effects of destroying the microbes, which can greatly increase the danger to the patient.
Use water pans during standard treatment sessions as described variously. See: Flu,. Chicken pox..