Boils and carbunclesFuruncles, carbuncles, abscesses and pus pimples – they all have to do with inflamed skin, but they differ. Thus, a boil resembles a pus pimple, but has penetrated deeper into the skin and is much more painful. If you have a boil, it is usually a good idea to seek medical treatment.
At a glance
– A boil is a purulent skin inflammation, caused by bacteria. In a boil, the hair follicles. The surrounding connective tie is inflamed. – If several boils merge, a carbuncle is formed. – A boil should never be squeezed by yourself – especially not on the face. – If the immune system is weakened, the risk of developing boils or other skin infections increases. – About 3 out of 100 people who go to their family doctor for a skin infection have a boil.
What is a boil?
A boil is a purulent skin inflammation caused by bacteria. It looks similar to a very large pus pimple. But the boil is located in deeper layers of the skin. Is much more painful than a pus pimple. Inflamed in a boil are the hair follicle. The surrounding connective tie. The hair follicle contains a hair, a hair root, a sebaceous gland – and a small muscle that can erect the hair. The hair follicle is also called hair follicle. That is why the inflammation in a boil is also called "deep folliculitis" and perifolliculitis.
If an infection occurs, the skin tie in the boil dies off. A cavity is formed, which is filled with pus: a so-called abscess. An abscess of the skin can develop from a boil. But it is also possible that an abscess arises from a severely inflamed insect bite or from injections with a contaminated needle. When several boils merge, a carbuncle is formed.
Sometimes a boil heals by itself and without problems. But often a medical treatment is useful. It can speed healing, relieve pain and protect against complications.
What are the symptoms of a boil?
A boil is noticeable as follows: You have a painful swelling that is the size of a cherry pit to a walnut. The swelling feels warm and is reddened. The pus can shimmer yellowish through the skin. If a carbuncle develops from several boils, the inflammation can also trigger a fever. Then you feel dull and groggy.
Boils occur primarily on the face, neck and throat. They can also form in other parts of the body: in the armpits or groin, on the back, in the pubic area, on the buttocks and on the thighs.
How does a boil happen?
Bacteria are the cause of a boil. Most commonly, it is the pathogen called Staphylococcus aureus. In many people, this bacterium occurs without causing any problems – on the skin or in the nasal mucosa, for example.
If the immune system is weakened, the risk of developing boils or other skin infections increases. People who have diabetes, a chronic infection or cancer, for example, are more likely to develop boils than a healthy person. Certain allergies such as allergic asthma, skin eczema and an inflamed conjunctiva also make boils more likely to occur.
How common is a boil?
Skin infections are very common. However, most inflammations of the skin have a different cause. A boil is present in about 3 out of every 100 people who see their primary care doctor for a skin infection.
When a boil develops, it takes hours to days to develop. After a few days, the pus comes out of the reddened and swollen lump. Once this happens, the boil heals within a few weeks – either on its own or after treatment. A small skin scar is left behind.
Sometimes a boil also heals without draining. Then the pus is broken down by the body.
What happens with a boil?
If you push or scratch a boil, the bacteria can spread through the body via blood vessels and lymph vessels. If, for example, a red stripe pulls away from the boil, the inflammation travels along the lymphatic channels – this is then referred to as lymphangitis. At the same time, the lymph nodes in the affected area may become painfully inflamed. This is called lymphadenitis.
For those who are not familiar, the red streaks in lymphangitis are sometimes thought to be signs of blood poisoning (sepsis). This serious and very rare complication only occurs when a large number of bacteria enter the bloodstream at once and when they spread quickly throughout the body.
Important to know: If you have boils on your face – especially around the nose and upper lip – there is some risk that the bacteria will be carried to the brain: And that the bacteria then lead to meningitis there – or to life-threatening blood clots in the large blood vessels, a so-called sinus vein thrombosis.
If people have a weakened immune system, boils can occur repeatedly – or in several places at the same time. Then one speaks of a so-called furunculosis.
A carbuncle, on the other hand, develops when several boils in neighboring hair follicles merge to form a larger focal point of pus. Such a carbuncle often occurs in the neck. It reaches deeper into the tie than a boil.
How to recognize boils?
As a rule, the doctor recognizes a boil by its typical appearance – and by the complaints that the affected person describes. If boils form frequently, if several boils occur at the same time, or if there is a fear of possible complications, further examinations – such as blood tests or a pus smear – may also be necessary.
The pus is examined in the laboratory. This is done for two reasons: One, so that you can determine exactly what kind of bacteria it is. On the other hand, so that antibiotics can be targeted. The blood is also examined. This helps to find out whether the inflammation has already spread and whether there may be certain pre-existing conditions that promote bacterial infections.
How to treat boils?
The doctor opens the pus abscess with a small incision. Then the wound is disinfected. Strips of cloth are placed inside. These strips absorb the pus and drain it away. The wound heals openly – so there is no need for suturing. If you have a boil, you should never push it out yourself – especially if the boil is on your face.
As long as a boil is growing, the abscess is not fully formed. The doctor can palpate it. In this phase, one can try to initiate or accelerate the ripening process – either with moist-warm compresses or with a so-called traction ointment.
Antibiotics are necessary if it is likely that complications will occur or if complications have already occurred – for example, if a carbuncle has developed from several boils. In the hospital, antibiotics are sometimes given as infusions.
Particularly important in the case of a carbuncle: it must be incised so that the pus can drain away. The larger wound is then additionally rinsed with antiseptic solutions – and this several times.
For more in-depth information on boils and carbuncles and how they are treated, see gesundheitsinformation.
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