In some cases the boil may smell unpleasant, which is usually when the boil drains and this is caused by the existence of bacteria within the pus.
If it does burst, a person may notice yellow, unpleasant-smelling pus.
It comes from the cells that form the walls of the cysts. Those cells secrete a protein, known as keratin. These cysts are also made of fat, and it's often that substance, or infection, that makes the smell, according to American Family Physician.
If the boil gets infected with the bacteria in the skin, it becomes an abscess filled with pus which has an unpleasant odor when it drains.
Other medical conditions or lifestyle factors that make people more likely to get boils include: iron deficiency anemia.
In some cases the boil may smell unpleasant, which is usually when the boil drains and this is caused by the existence of bacteria within the pus.
One sign of infection is redness and swelling around the cyst or foul-smelling drainage seeping out of the cyst. See your healthcare provider if you have such symptoms.
If the cyst breaks open, the material inside it often smells bad too. The cyst is usually firm and you can usually move it slightly if you try. The cyst can be smaller than a pea or as large as a few inches. It's usually not painful, unless it becomes inflamed or infected.
Risk factors for boils
Poor hygiene – sweat and dead skin cells in natural creases and crevices, such as the armpit, provide a hospitable home for bacteria. Nutrition – inadequate nutrition may reduce a person's natural immunity. Broken skin – other skin conditions, such as eczema, can break the skin surface.
Boils near the vagina are caused by bacteria that enter through the skin and infect a hair follicle. Keeping your genital area clean and practicing good hygiene is the best way to prevent recurring boils. If you shave your pubic area with a razor, change your razor often.
When the boil bursts, cover it with sterile gauze or a dressing. This is to prevent the spread of infection. Afterwards, wash your hands thoroughly using hot water and soap. Never squeeze or pierce a boil because it could spread the infection.
When these cysts or boils erupt, there may be a noticeable odor. The pus smell comes from the bacteria that have been trapped under the skin inside the boil. These bacteria, called anaerobic bacteria, live without oxygen and can thrive under the skin before they erupt.
The keratin they secrete accumulates in the center of the cavity, as a dense yellowish paste. If the cyst breaks or is squeezed it will ooze keratin.
Do not squeeze the cyst or poke it with a needle to open it. This can cause swelling, redness, and infection. Always have a doctor look at any new lumps you get to make sure that they are not serious.
The cysts usually contain keratin, lipid, and other skin particles. Cysts can remain stable or they may steadily grow. Sometimes they will become inflamed or suddenly break open (rupture). This poses a risk for infection.
What is an abscess? An abscess is a collection of pus. Pus is a thick fluid that usually contains white blood cells, dead tissue and germs (bacteria). The pus may be yellow or green and may have a bad smell.
If left untreated, benign cysts can cause serious complications including: Infection – the cyst fills with bacteria and pus, and becomes an abscess. If the abscess bursts inside the body, there is a risk of blood poisoning (septicaemia).
Pus appears green due to an antibacterial protein called myeloperoxidase. It's made by certain white blood cells. Green pus is a potential warning sign of a pseudomonas bacterial infection caused by a bacterium called Pseudomonas aeruginosa. This color of pus is often accompanied by a foul odor.