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Medical
Dermatology - Infections
Bacterial infections
Humans
are natural hosts for many
bacterial species that
colonize the skin as
normal flora.
Staphylococcus aureus and
Streptococcus pyogenes are
infrequent resident flora,
but they account for a
wide variety of bacterial
pyodermas. Predisposing
factors to infection
include minor trauma,
preexisting skin disease,
poor hygiene, and, rarely,
impaired host immunity.
Fungal
and yeast infections
Three
fungal genera—Trichophyton,
Microsporum, and
Epidermophyton—account for
the vast majority of
infections. Fungal
reservoirs for these
organisms include soil,
animals, and infected
humans.
Viral
infections
Herpes
simplex virus (HSV)
infection is a painful,
self-limited, often
recurrent dermatitis,
characterized by small
grouped vesicles on an
erythematous base.
Eighty-five percent of the
population has antibody
evidence of HSV type 1
infection. HSV type 2
infection is responsible
for 20% to 50% of genital
ulcerations.
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