N–O
necrotizing fasciitis A rare but serious bacterial
INFECTIONof the fascia, the layer of connective tis-
sue that covers, separates, and connects the mus-
cles and other musculoskeletal structures. In
necrotizing fasciitis a combination of aerobic and
anaerobic bacterial activity produces an abun-
dance of nitrogen, hydrogen, and methane gases.
These gases act to suppress the activity of white
BLOODcells that ordinarily would move in to fight
the infection. Necrotizing fasciitis is most com-
monly an OPPORTUNISTIC INFECTIONthat develops in
people who have DIABETES, HIV/AIDS, and other cir-
cumstances of immunocompromise.
Nearly always the infection arises at or near the
site of a wound, either accidental (more common)
or surgical. Symptoms include sudden, severe PAIN
at the site along with redness and slight swelling.
The person generally feels and looks well in the
early stages of the infection, then suddenly
becomes critically ill. The redness of the RASH
becomes purple, and the SKINis odd to the touch.
Often there is loss of sensation (traumatic ANESTHE-
SIA) in the area. Necrotizing fasciitis moves very
rapidly along the fascia into the deep tissues; the
farther into the body it goes, the faster its progres-
sion because the anaerobic conditions (lack of
oxygen) support its growth. Diagnosis is difficult
in the early stages but unmistakable in the later
stages. Blood cultures and cultures of tissue sam-
ples from the innermost edges of the infection
generally reveal the causative BACTERIA, which
allows doctors to choose effective ANTIBIOTIC MED-
ICATIONS.
Treatment is multifocused and includes intra-
venous antibiotics, usually multiple drugs, to
attack the various types of bacteria involved in the
infection as well as surgery to expose the infection
to air (which reduces the ability of anaerobic bac-
teria to flourish) and remove dead and infected
tissue so only healthy tissue remains. The surgical
wounds are often significantly larger than the sur-
face appearance of the infection would suggest
because so much of the infection is deep within
the body. Multiple operations are often necessary.
Treatment with hyperbaric oxygen speeds
improvement in some people.
With early detection and aggressive treatment
that keeps necrotizing fasciitis fairly localized, the
likelihood for recovery is good. When infection is
extensive and other health conditions exist that
challenge the IMMUNE RESPONSE, about 20 percent of
people survive necrotizing fasciitis. Because
researchers do not understand the complexity of
circumstances that allows necrotizing fasciitis to
develop, there are no methods for preventing infec-
tion. People who have any degree of immunocom-
promise should carefully monitor any wounds and
seek prompt medical care for those that do not
seem to follow a normal path of HEALING.
See also ANTIBIOTIC RESISTANCE; BOTULISM;GAN-
GRENE; IMMUNOCOMPROMISED.normal flora The BACTERIA, fungi, and other
microorganisms naturally present within the envi-
ronment of the healthy body. Normal flora exist
on the surface of the SKIN, within natural cavities
such as the NOSEand MOUTH, in the gastrointestinal
tract, and in the reproductive tract. These benefi-
cial microbes participate in the body’s IMMUNE
RESPONSE, digestive functions, and reproductive
functions, among others.
Normal flora microbes exist in a balance that
prevents one type of MICROBEfrom overpowering
another. Circumstances that change this balance
may allow illness to develop. Antibiotic therapy
targets bacteria, for example, though antibiotics346