Cellulitis
is a bacterial infection of the deep layer of skin (dermis)
and the layer of fat and soft tissues (the subcutaneous
tissues) that lie underneath the skin. The condition is
similar to erysipelas, which only affects the skin itself and
the tissues nearer to the surface.
Cellulitis
is not to be confused with cellulite, which is a cosmetic
problem.
A variety
of bacteria groups live on the skin's surface but do not
normally cause any problems. Usually the bacteria are not
concentrated enough to do any harm, but sometimes they pass
deeper into the skin and establish an
infection.
Two of
these groups of micro organisms, streptococci and
staphylococci, are generally the main cause of cellulitis.
These two groups are among the most common bacteria that cause
infections in humans.
The
bacteria enter the skin through any damaged areas, like a
spot, cut, wound or via a skin condition such as eczema or a
leg ulcer. Once it is inside the skin, the bacteria produce
powerful enzymes that break down the natural barriers that
normally prevent bacteria spreading in the tissue. This allows
infection and inflammation to spread. Any area of the body can
be affected but the leg is the most common
region.
