MadSci Network: Medicine |
Dear Kia,
Thank you for your questions about skin infections. Skin infections are
caused by tiny bacteria. These bacteria and how they cause infections are
very interesting.
What kind of bacteria cause skin infections? Skin infections can
be caused by many different kinds of bacteria. The most common kind is
named Staphylococcus epidermis, but most people call it
Staph for short.
Where does Staph come from? Everybody has Staph bacteria
all over their bodes! These bacteria live there all the time. Some will
even stay on your skin after you take a shower! Everyone has Staph
on their bodies, but not everyone has infections.
How does Staph cause infections? Our skin is an amazing
organ. It can do so many things! One important job of skin is to keep
bacteria on the outside of our bodies. Usually it works very, very well.
Sometimes, however, the skin breaks, like when you fall and scrape your
knee, or cut yourself on a sharp object.
When your skin breaks, the Staph bacteria get inside your body.
Fortunately, we have a very powerful immune system to stop bacteria that
get past our skin. But sometimes the bacteria are very difficult to stop
once they're under the skin. They keep growing and growing, which causes
damage to our bodies.
You have an infection from the time the bacteria get under your skin until
the time your immune system kills all of the bacteria. Signs that your
immune system is working against bacteria that got under the skin include
redness, swelling, and tenderness. If an infection gets out of control,
your body may even turn up your temperature to help stop the bacteria.
(Hopefully you would have seen a doctor to help you as soon as you saw the
redness, so that you wouldn't have gotten to this dangerous stage of skin
infections.)
Can band-aids prevent infections? Most infections are caused by
bacteria that enter your wound right when you get cut. So a band-aid
would not stop the infection from starting. However, a band-aid might be
a good idea to prevent dirt from getting into the cut, which could make
the situation worse. A band-aid might also help hold the skin together in
case you bump your cut before it's healed enough to hold together. If the
cut reopens, then bacteria might get into it and start an infection. On
the other hand, fresh air also helps keep the wound from getting too damp,
and stops bacteria from growing quickly. Different people use band-aids
at different times.
Do scabs prevent infections? The main purpose of a scab is to plug
up the cut to stop it from bleeding. However, it also helps to cover the
scrape or cut and prevent the wound from reopening. If the wound reopens,
more bacteria might get inside, and cause an infection. Scabs are
definitely good to help your skin heal quickly, so it's better to leave
them on as long as possible.
Why does it hurt when you wash a cut? There are many nerves in your
skin. Some of those nerves are deeper inside your skin than others. Some
of the deep nerves are pain nerves. It is the job of these pain nerves to
let you know when you have an injury to your skin. When you wash your
cut, the water presses on these pain nerves, and causes you to feel pain.
It is important to keep your scrapes clean, so you may need to wash them
every once in a while.
Information about how to care for your cuts and scrapes can be found on
the web site of the University of Iowa's School of
Nursing
You might also find these MAD Scientist essays interesting:
What
kind of bacteria is under your fingernails?
What
kind of bacteria grows in your hair?
Which
types of bacteria are most commonly found on the human hand?
How
many microorganisms do we have on the surface of our skin?
I find infections very interesting. If you would like to know more,
please ask MadSci Network more questions!
Sincerely yours,
John Carlson
MAD Scientist
Try the links in the MadSci Library for more information on Medicine.