chapter21 Flashcards
name examples of normal microbiota of the skin?
Gram positive bacteria:
cutibacterium acnes
corynebacterium xerosis
Yeast:
malassezia furfur
does cutibacterium acnes require oxygen?
No it’s anaerobic
does corynebacterium xerosis require oxygen?
yes its aerobic
what bacteria of the skin microbiota produces acids to maintain low skin pH?
cutibacterium acnes
small fluid filled lesions are….
vesicles
flat reddened lesions are…
macules
vesicles larger than 1cm in diameter are called….
bullae
skin rash raising from a disease is called?
exanthem
rash on mucous membranes due to a disease is called?
enanthem
raised lesions are called?
papules
raised lesions with pus?
pastules
whats the enzyme used for identification of certain types of staphylococci?
coagulase
enzyme that clots fibrin in the blood?
coagulase
name a coagulase negative staphylococci?
staphylococcus epidermidis
90% of skin microbiota is….?
staphylococcus epidermidis
name a coagulase positive bacteria of skin microbiota?
S. aureus
name 2 special strains of s. aureus
MRSA (methicillin resistant) which is also antibiotic resistant
VRSA (vancomycin resistant)
skin bacteria that could cause sepsis?
s. aureus
Name all seven staphylococcal skin infections?
folliculitis
sty
furuncle (boil)
carbuncule
nonbullous impetigo
scalded skin syndrome
toxic shock syndrome
infection of hair follicles is called
folliculitis
crusting sores of the skin spread by autoinculcation is called?
impetigo
localized region of pus surrounded by inflamed tissue which is also a type of abscess is called?
furuncle
folliculitis of eyelashes
sty
a spreading furuncle which causes inflammation and damage to deep tissue is called
carbuncle
major pyogenic skin infections?
furuncle and carbuncle
minor skin infection?
folliculitis and boil
bullous impetigo is also called
scalded skin syndrome
impetigo of the newborn is also called
pemphigus neonatorum
what causes exfoliation of the skin in scalded skin syndrome
toxin B
fever, vomiting, shock and organ failure are all symptoms of
toxic shock syndrome
which toxin causes fever, vomiting, shock and organ failure if present in bloodstream?
TSST-1 (toxic shock syndrome toxin 1)
streptococci are gram….
positive
a substance produced by streptococci and causes RBC lysis?
hemolysins
which type of streptococci often causes disease?
beta hemolytic streptococci
streptococci are differentiated into groups A-T based on….
Antigenic cell wall carbohydrates
Group A streptococci (GAS) are also called?
streptococcus pyogenes
how many types does GAS include
80 immunological types
Name all virulence factors in streptococcus pyogenes
streptolysins
M protein
hyaluronidase
streptokinase
part of s. pyogenes that dissolves connective tissue?
hyaluronidase
…… is external to the s. pyogenes cell wall and allows adherence and immune system avoidance
M protein
lyses blood CLOTS
streptokinase
lyses RBCs
streptolysins
give examples of streptococcal skin infections?
erysipelas
necrotizing fasciitis
streptococcal toxic shock
what bacteria causes erysipelas and necrotizing fasciitis?
S. pyogenes
what part of skin does s. pyogenes infect in erysipelas?
the dermal layer
local tissue destruction and sepsis are signs of?
erysipelas
flesh eating disease that causes rapid tissue destruction ?
necrotizing fasciitis
the superantigen that causes necrotizing fasciitis
Exotoxin A produced by S. pyogenes
does pseudomonas aeruginosa require oxygen?
yes its aerobic
pseudomonas aeruginosa is gram….
negative
pseudomonas aeruginosa is … shaped
rod
the substance produced by pseudomonas aeruginosa and produces blue green pus is called…
pyocyanin
what types of toxins are produced by P. aeruginosa
endotoxins and exotoxins
name 2 disease caused by P. aeruginosa
otitis externa
pseudomonas dermatitis
self limiting rash usually acquired by swimming pools is called
pseudomonas dermatitis
swimmer’s ear caused by P. aeruginosa is also called
otitis externa
pseudomonads are ….. pathogens in burn patients
opportunistic
buruli ulcers are caused by
mycobacterium ulcerans
toxin produced by mycobacterium ulcerans and enters via a break of the skin or an insect bite
mycolactone
deep damaging ulcers that may require amputation are called
buruli ulcers
buruli ulcers are primarily found in
western and central africa
most common skin disease in humans
Acne
what process develops acne?
when skin cells shed in high numbers and combine with sebum
which clogs the follicles
whiteheads form because of …. accumulation
sebum
when the blockage protrudes through the skin its called a
black head
the dark color of blackheads is due to…
lipid oxidation
what are the 3 main types of acne from the least to most severe
comedonal acne
inflammatory acne
nodular cystic acne
inflammatory acne is caused by…
propionibacterium acnes (P. acnes)
how does P. acnes cause inflammatory acne
P. acnes metabolizes sebum and produces fatty acids which produce an inflammatory response
treatment of inflammatory acne includes
benzoyl peroxide and antibiotics
inflamed lesions with pus deep in the skin are signs of …. acne
nodular cystic (severe)
give examples of VIRAL skin infections
warts
smallpox
chickenpox
shingles
herpes simplex
measles
warts are also called
papillomas, which are small skin growths
warts are transmitted via
direct contact
the virus causes warts is called
papillomavirus
which types of human papillomavirus can cause skin and cervical cancer
HPV 16
HPV 18
treatment of warts includes
cryotherapy (cold liquid nitrogen)
electrodesiccation (drying with electrical current)
burning with salicylic acid
smallpox (variola) is caused by…..
orthropoxvirus
what are the 2 forms of of variola
variola major (20-60% mortality)
variola minor (<1% mortality)
how is smallpox transmitted?
via the respiratory route
moves into the bloodstream and infects cells
monkeypox is prevented by
smallpox vaccine
the virus causing chickenpox is called
herpesvirus varicella zoster
varicella zoster is transmitted via
respiratory route
whats the appearance of chickenpox?
pus filled vesicles
severe complication of chickenpox that causes vomiting and brain dysfunction is called
reye’s syndrome
use of … increases the risk of reye’s syndrome
Aspirin
herpesvirus varicella zoster becomes latent in….
central nerve ganglia
herpesvirus varicella zoster becomes indefinitely latent in
dorsal root ganglion
shingles (herpes zoster) is caused by?
reactivation of latent herpesvirus varicella zoster that moves along peripheral nerves to the skin and then affects cutaneous sensory nerves
varicella zoster is reactivated due to
stress or lowered immunity
complications of shingles include
Post-herpetic neuralgia
shingles can be prevented by
zoster vaccine
herpes simplex is caused by
human herpesvirus 1 and 2
HSV1 and HSV2
HSV-1 is primarily spread by…
oral or respiratory route
HSV-2 is primarily spread…
sexually
signs of infection with HSV-1 include…
fever blisters and cold sores
HSV-1 remains latent in …
trigeminal nerve ganglia
HSV-2 remains latent in …
sacral nerve ganglia near the spine
outbreaks of HSV-1 could be triggered by..
sun, hormonal changes or stress
pregnant women with HSV-2 should deliver by…
caesarean
vesicles on the skin caused by herpesvirus are called
herpes gladiatorum
vesicles on the fingers caused by human herpesvirus HSV are called
herpetic whitlow
the case in which HSV spreads to the brain is called
herpes encephalitis
measles (rubeola) is transmitted by…
respiratory route
macular rash and cold like symptoms are signs of infections with…
measles
Koplik’s spots are…
red spots in the oral mucosa opposite the molars and caused by measles
a rare complication of measles that occurs 1-10 years after recovery is called…
subacute sclerosisng panencephalitis
vaccine that prevents measles and subacute sclerosing panencephalitis is called?
MMR vacine (measles, mumps, rubella)
rubella or german measles is caused by
rubella virus
rubella is transmitted by…
respiratory route
symptoms of rubella include
light fever and macular rash
incubation time for rubella?
2-3 weeks
signs of congenital rubella syndrome include
heart defects, mental retardation, fetal damage and deafness
rubella is prevented by
MMR vaccine
which people cant receive the MMR vaccine?
children under 1 year old
pregnant women
slapped cheek facial rash is a sign of?
erythema infectiosum
erythema infectiosum (fifth disease) is caused by
human parvovirus B19
roseola is caused by
human herpesvirus 6 and 7
symptoms of roseola include
high fever and body rash
how long does it take to recover from roseola?
1-2 days
enterovirus can cause a disease called…
hand foot and mouth disease
hand foot and mouth disease is spread by..
mucous and saliva usually in children
fungal infection in th body is called
mycosis
fungal infection that affects outer epidermis of skin, hair and nails is callee?
cutaneous mycoses
cutaneous mycoses are caused by
fungi that metabolize keratin
dermatomycosis are informally known as
ringworms or tineas
scalp ringworm is called
tinea capitis
atheletes foot is called
tinea pedis
ringworm of nails is called
tinea unguium
tinea cruris is called
jock itch
name three genera of fungi that cause cutaneous mycoses
epidermophyton
trichophyton
microsporum
subcutaneous mycoses penetrate which layer of the skin?
stratum corneum
what type of infection does fungi that inhabit the soil usually cause
subcutaneous mycoses
sporotrichosis is a type of …. mycoses
subcutaneous
what fungus causes sporotrichosis?
sporothrix schenkii (dimorphic)
overgrowth of C. albicans is called
candidiasis
structure that makes C. albicans resistant to phagocytosis
pseudohyphae
where does candidiasis mostly occur ?
mucous membranes of the genitourinary tract and mouth
skin
form of candidiasis that affects newborns?
thrush: whitish overgrowth in the oral cavity
give examples of parasitic infections of the skin?
scabies الجرب
pediculosis القمل
the parasite that causes scabies is called…
sarcoptes scabiei mites
sarcoptes scabiei mites are transmitted via…
intimate contact
describe the appearance of scabies?
inflammatory skin lesions caused by the parasites laying eggs in the skin
what are the two parasites that cause pediculosis?
pediculus humanus capitis (head lice) P. h. capitis
pediculus humanus corporis (body lice) P. h. corporis
give examples of microbial diseases of the eye?
conjunctivitis
ophthalmia neonatorum
inclusion conjunctivitis
trachoma
keratitis
pink eye / red eye are possibly caused by?
conjunctivitis (inflammation of eye membrane)
what do you know about haemophilus influenzae?
it causes conjunctivitis
its not connected to influenza infections
name all microbes that can cause conjunctivitis?
haemophilus influenzae
pseudomonads associated with unsanitary contact lenses
adenoviruses
ophthalmia neonatorum is caused by?
Neisseria gonorrhoeae
describe the symptoms of ophthalmia neonatorum
large amounts of pus, ulcers of the cornea
Chlamydia trachomatis can cause different diseases in the eye, name two of them
inclusion conjunctivitis
trachoma
name two diseases that can be transmitted to newborns eyes from the birth canal?
ophthalmia neonatorum
inclusion conjunctivitis
chalmydia trachomatis in the case of trachoma is transmitted by?
hand contact or flies
describe the results of trachoma in the eye?
permanent scarring of corneas
possibly blindness
inflammation of the cornea is called
keratitis
keratitis can be caused by
bacteria in the USA
fungi (fusarium and aspergillus) in Africa and Asia
herptic keratitis is caused by
HSV-1 (herpes simplex virus 1)
a virus that can cause a skin and an eye infection?
herpes simplex virus 1
acanthamoeba keratitis is caused by
ameba transmitted via water and soil
unsanitary contact lenses can cause 2 different eye infections which are
conjunctivitis
acanthamoeba keratitis