The formation of a simple boil, or furuncle, is caused by the invasion into the deeper layers of the skin of germs which are constantly present on the surface of the skin, and the accumulation of white blood cells brought to the spot to destroy these germs and wall them off to prevent their further spread. This accumulation of white cells is the pus, which constitutes the core of the boil.
The question arises in what way and under what circumstances do the germs invade the lower layers of the skin? This question is easier to ask than it is to answer. It is possible the answer is that the germs which cause boils, although they look exactly like the germs which are constantly present on the surface of the skin, are, in reality, a different and special kind. And when these special germs get into contact with the skin a furuncle results.
Or it may be that under certain circumstances the body is run down and the normal resistance to germs is lessened and in that way the infection gets a foothold. We know that this is true, for instance, in diabetes, and that it is not at all uncommon to see people who have diabetes with crops of boils. In fact, it is a regular rule for a physician who finds a patient with many crops of boils, to make an examination to see whether or not there is any diabetes present.
All simple or single boils should be treated as early as possible, because there is a tendency once the skin is invaded for a number of boils to form in the same spot. This is particularly true in the familiar case of boils on the back of the neck.
In the treatment of boils, the old fundamental rule of surgery always is invoked”Ubi pus, ubi evacuo””Wherever there is pus, there it must be evacuated.”
As a matter of fundamental common experience it is wiser to allow the boil to ripen and to open it when the pus has been definitely formed. The reason for this is that at that time there is usually a sort of protective wall formed by nature around the pus so that an incision into it at that time will not open up channels of spread through the rest of the body.
In the treatment of recurrent crops of boils, or several at one time, besides this principle of evacuation there must be attempts to raise the general resistance of the body to prevent re-infection. This can be done in various ways. Sometimes a poultice, or better, an ice pack, is placed over the affected region. Sometimes a method suggested by a German surgeon several years ago called, “Bier’s hyperemia,” in which the suction is made by cups with air bulb attachments, on the affected area. Sometimes the use of vaccines made from the germs causing the boils will bring the patient’s resistance up so that the invasion is halted.