Un boil corresponds to the deep infection of the base of a hair, the pilosebaceous follicle, due to a bacterium, which in the vast majority of cases is Staphylococcus aureus (S. aureus).

The boil is a big button very painful, initially red and hard, which quickly turns into pustule (= white-headed pimple containing pus).

Boils can form all over the body. They heal in a few days, provided they have followed an adequate treatment.

In some cases, several boils appear in the same place. We then speak ofAnthrax, a grouping of several boils affecting neighboring pilosebaceous follicles, occurring mainly in the upper back.

Who is affected by boils?

Boils are very common and they affect men and adolescents more.

The hairy areas subject to friction are the most affected: beard, armpit, back and shoulders, buttocks, thighs.

It is difficult to accurately estimate the prevalence of boils, but skin infections associated with Staphylococcus aureus (which include other infections such as abscesses, folliculitis or erysipelas) account for up to 70% of the skin infections that must be caused. treating dermatologists in France¹.

Causes of boils

Boils are almost always caused by a bacteria called Staphylococcus aureus (Staphylococcus aureus), which is widespread in the environment but also lives in humans, on the skin, in the nasal passages or the digestive tract.

About 30% of adults are permanent “carriers” of Staphylococcus aureus, which means that they “harbor” it continuously, especially in the nasal cavity, without developing infection.

However, Staphylococcus aureus produces harmful toxins and therefore can be very dangerous, infecting the skin, but also internal organs or the blood in some cases.

For several years now, staphylococci aureus have become increasingly resistant to antibiotics and represent a growing threat, especially in hospitals.

Course and possible complications of boils

Most often, a simple, well-groomed boil heals within a few days, however, leaving a scar. THE’Anthrax (grouping of several boils) requires more intensive treatment and may take longer to heal.

Complications are rare, although it is common for a boil to reappear in the same place a few months or even a few years later.

In some cases, especially in people with weakened immune systems, a boil can cause potentially serious complications:

• a furonculose, characterized by multiple repeated boils, which recur and persist over periods of several months
• a severe infection : the bacteria can spread in the blood (= septicemia) and to various internal organs if an improperly treated boil gets worse. Fortunately, these complications are very rare.