Bacteria skin infections Flashcards
Functions of the skin
Prevents excessive ______
Important to _____ regulation
Involved in _____ phenomena
Barrier against __________
water loss
temperature
sensory
microbial invaders
Wounds allow microbes to infect deeper tissues
T/F
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The skin has normal flora just like any other part of the body
T/F
T
The skin’s flora is composed of _______,________, and ________ bacteria etc
aerobic cocci, aerobic and anaerobic coryneform
Major function of skin flora is to ___________ by Providing __________ for pathogenic microorganism
By hydrolizing ______ of _____ to produce _________ which are toxic to many bacteria
prevent skin infections
ecological competition
lipids of sebum
free fatty acids
Microbiota
____tolerant
Dense populations in skin _____
Total numbers determined by ________ and _________
May be opportunistic pathogens
Halo
folds
location and moisture content
The ecology of particular areas of the skin is determined by the availability of moisture, presence of sebaceous lipids, and gaseous environment
T/F
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Skin
The process of infection involves the interaction between two organisms-the host and the invader
The clinical changes depends on the organisms, its virulence, and patient’s immunity
T/F
T
T
INTRODUCTION
(Acute or Chronic?) bacteria infections generally produce some or all of the classical features of acute inflammation
These cardinal signs includes;
________,_________,__________,_________
Acute
erythema(redness), swelling/oedema, heat/warmth, pain/discomfort
Most skin flora categorized in three groups:
————
__________
___________
Diphtheroids
Staphylococci
Yeasts
Most skin flora categorized in three groups:
Diphtheroids (_________ and ________)
Staphylococci (Staphylococcus _____)
Yeasts (______ and _______)
Corynebacterium and Propionibacterium
epidermidis
Candida and Malassezia
Bacteria skin infections are very (common or rare?)
Common
____,__________, and ________ are the most common bacteria skin infections
Carbuncles,
Cellulitis, impetigo and folliculitis
Impetigo: infection of _______Layer of epidermis
Ecthyma: infection of ____________ Of epidermis
Erysipelas: infection of _________
sub corneal
full thickness
upper half dermis
Cellulitis : infection of the ________
Necrotizing factors: infection of ______ and ______
lower half of dermis
subcutaneous fat and deep fascia
FOLLICULITIS
Introduction- folliculitis is infection of the ________.
Classification is by the _______of the hair
follicles which could be ______ or ______ folliculitis.
hair follicles
depth of involvement
superficial or deep
FOLLICULITIS
Hair follicle can become inflamed by ______ injury, _______ or infection that leads to folliculitis.
physical; chemical irritation
A furuncle develops when the ________ and ____________ are involved.
entire follicle
surrounding tissues
Folliculitis: Causative Agent
Most commonly caused by ______
_____ tolerant
Tolerant of _______
Staphylococcus
Salt
desiccation
Signs and symptoms of folliculitis
Infection of the hair follicle often called a _________
Called a _____ when it occurs at the eyelid base
Spread of the infection can produce _________ or ________
pimple
sty
furuncles or carbuncles
Epidemiology and pathogenesis Of skin infections
The most common form is ______________
It could be multiple or single lesion and can appear on any ———————including head, neck, trunk,buttocks and extremities
superficial folliculitis
skin bearing hair
Epidemiology and pathogenesis Of skin infections
commensal organisms like ____ can be seen in immunocompromised.
Occasionally, gram negative folliculitis can be seen in ________ patients treated with (short or long?) courses of antibiotics.
yeast
acne vulgaris
Long
Epidemiology and Pathogenesis Of skin infections
The use of hot tubs and whirl pools has been classically associated with __________.
Patients with _________ are at increased risk because of higher rate of colonization with S. aureus.
______,________, or _________hair, use of topical _______, hot and humid weather, and diabetes mellitus are all predisposing factors
.
Pseudomonas folliculitis
atopic dermatitis
Shaving, plucking or waxing
corticosteroids
Clinical features of bacterial skin infections
A (shallow or deep?? folliculitis appears as (small or large?) , tender, erythematous _____, often with a _______.
The lesions may be ________ and slighly tender. The lesions are ______ and may scar.
Deep ; large
papules; central pustule.
pruritic; painful
Diagnosis and Differential diagnosis
The diagnosis of bacterial folliculitis is usually based on ______
Gram stain and bacterial cultures can help to identify the causative organisms, especially in recurrent or treatment-resistant cases.
The differential diagnosis includes other forms of folliculitis as well as ___________,__________,____________ and _________
clinical inspection.
acne vulgaris, rosacea, ,pseudofolliculitis barbae , and keratosis pilaris
TREATMENT of skin infections
antibacterial washes that contain _______ or _______
Antibacterial ointments (_______ or __________ 2%)
chlorhexidine or triclosan.
bacitracin or mupirocin
Treatment of skin infections
appropriate oral b-lactamase inhibitor antibiotics, _______ and ________ (e.g clindamycin), _______ can be used for serious cases.
macrolides and lincosamides
flouroquinolones
PSEUDOMONAL FOLLICULITIS
Pseudomonal folliculitis is associated with the use of _________,_______ and, rarely, ____________.
whirlpools, hot tubs
swimming pools
PSEUDOMONAL FOLLICULITIS
P.________ gains entry via ________ or _____ in the skin.
The lesions arise _____ after exposure and resolve in ________
aeruginosa
hair follicles; breaks
8–48 hours
7–14 days.
Clinical features of Pseudomonal folliculitis
Associated symptoms do not imply __________ of P. aeruginosa
These symptoms includes ; __________,_______,_________
systemic spread
painful eyes, malaise, fever
Diagnosis of Pseudomonal folliculitis
The diagnosis can be confirmed by isolation of P. aeruginosa, especially serotype ______, from lesions.
The differential diagnosis includes _____________ folliculitis, insect bites, ________,___________, ________ folliculitis, miliaria and acne vulgaris.
O-11
S. aureus
papular urticaria, Majocchi’s granuloma
eosinophilic
TREATMENT
Treatment is generally not indicated in immunocompetent hosts as it is usually a self-limited process.
Lesions usually resolves spontaneously within seven to ten days
In the case of widespread eruptions, recurrences, immunosuppression or associated systemic symptoms, an oral fluoroquinolone and topical gentamicin can be used.
TREATMENT
Treatment is generally not indicated in immunocompetent hosts as it is usually a self-limited process.
Lesions usually resolves spontaneously within seven to ten days
In the case of widespread eruptions, recurrences, immunosuppression or associated systemic symptoms, an oral fluoroquinolone and topical gentamicin can be used.
PREVENTION of Pseudomonal folliculitis
Personal hygiene and maintenance of _____ and _______
Hand hygiene
Avoid sharing of _______
pools and tubs
towels
Furuncles and Carbuncles
A furuncle is a ______,_________ , firm or fluctuant mass of _______ ———- material arising from the _________.
It is commonly known as ______ or ________
tender, erythematous
walled-off ; purulent
hair follicles
boil or abscess.
Furuncles and Carbuncles
Carbuncles are an aggregate of ____________________ that form (broad or narrow?) (flat or swollen?) , erythematous, (shallow or deep?) and (painful or painless?) masses that usually open and drain through ________.
infected hair follicles
Broad; swollen; deep; painful
multiple tracts
Furuncles
extended ______,_______, _______ and tenderness
Carbuncles
Numerous sites of _________, Usually in areas of ________ skin
redness, pus, swelling
draining pus; thicker
EPIDEMIOLOGY AND PATHOGENESIS
Furuncles tend to occur in _______ and __________
________ is the most common causative organism, though recurrent furuncles in the _________ region can be secondary to (aerobic or anaerobic?) bacteria.
adolescents and young adults.
S. aureus ; anogenital region
anaerobic
Five percent of cutaneous abscesses are ______, caused by a _________ reaction (e.g. _______________)
sterile
foreign body
ruptured cyst
Furuncles
Predisposing factors include (acute or chronic?) _______ carriage,
Diabetes mellitus, obesity, poor hygiene,
Immunodeficiency states, such as in chronic granulomatous disease and ____ syndrome.
Chronic
S. aureus
Job
Furuncles
The most common locations are the ___,______,______ ,______,_______ and perineum. Sites prone to ______ or _____ , such as the area ______, are distinctly susceptible.
face, neck, axillae, buttocks, thighs
friction or minor trauma
under a belt
Furuncles usually begin as a _____,_____, red nodule that ______ and becomes ______ and _________; _______ results in decreased pain.
hard, tender
enlarges
painful and fluctuant
rupture
Furuncles
Epidemiology: endogenous
Two species commonly found on the skin
– ________ ————
– _______ ————
Transmitted through _________ or _______
Staphylococcus epidermidis
Staphylococcus aureus
direct or indirect contact
Treatment of furuncles
________ (semi-synthetic penicillin)
______ or _______ used to treat resistant strains
May require —————-
– Prevention of furuncles
Hand _______
Proper ——————- and surgical openings, aseptic use of catheters or indwelling needles, and appropriate use of antiseptics
Dicloxacillin
Vancomycin or Bactrim
surgical draining
antisepsis; cleansing of wounds
Scalded Skin Syndrome
__________ scalded skin syndrome (SSSS)
Bacterial agent is __________
——— mediated disease
Staphylococcal
Staphylococcus aureus
Toxin
Signs & Symptoms of SSSS
•Skin appears ———- (______)
–Other symptoms include malaise, irritability, fever; nose, mouth and genitalia may be _______
burned; scalded
painful
SSSS
__________ toxin released at infection site
causes ——- in epidermis
– (Inner or Outer?) layer of skin is lost
-Causes ____ loss and increase susceptibility to __________
Exfolative
split
Outer
body fluid; secondary infection
Epidemiology of SSSS
–___% of S. aureus strains produce _______
– Disease can appear at any age group
•Most frequently seen in ______,_______ and immunocompromised
– Transmission is generally _________
5; exfoliatins
infants, the elderly
person-to-person
Impetigo (________)
Characterized by ____ production
Pyoderma
pus
Impetigo
Causative agents:
– _________ ______
– 80% cases caused by ________
– Others caused by _______ _______
Pyodermic cocci
S. aureus
Streptococcus pyogenes
Impetigo
– Others caused by Streptococcus pyogenes
Group ___ Streptococcus
– Gram- ______ coccus, arranged in _____, __ -hemolytic
A; positive
chains; β
Signs & Symptoms of impetigo
•(Superficial or deep?) skin infection
•Blisters just below ________ layer
•Blisters replaced by _________
•There is little ______ or _____
•Lymph nodes enlarge near area
•May result in _______
Superficial ; outer skin layer
weepy yellow crust
fever or pain
erysipelas
Epidemiology of impetigo
– most prevalent among (children or adult?)
Most affected are ______ years of age
– Disease primarily spread from __________
Also spread by ————-
Children
two to six
person-to-person
insects and fomites
Prevention and treatment of impetigo
– Prevention is directed at ________ and ________ of individuals with impetigo
– ________ treatment of wounds and application of ________ can lessen chance of infection
– Active cases are treated with ________, ________ or ________
cleanliness and avoidance
Prompt ;antiseptics
penicillin, erythromycin or vancomycin
Acne
_______-associated lesion
Causative agent
Most serious cases caused by __________ ————
– Epidemiology: ____genous
Follicle
Propionibacterium acnes
endogenous
Acne
Propionibacterium acnes
–
Gram- _______,
______-shaped ______
feed on ______ and ______ in ______ pores & ______
positive; rod
diphtheroids
sebum ; keratin
plugged ; follicles
Prevention of Acnes
remove ______ as often as possible
oils
Treatment of impetigo
•prophylactic _________
•_________ or _________ acid
•New treatment uses _________ ________
•_________ in severe cases
tetracycline
Benzoly peroxide ; salicylic acid
blue light radiation
Accutane
ERYSIPELAS
Erysipelas is primarily an infection of the _______ with significant _______ involvement.
It has a distinctive clinical presentation and is most often caused by ________ _______ (group ___ streptococci).
dermis , lymphatic involvement.
Str. pyogenes (group A streptococci).
Pathogenesis and Epidemiology of Erysipelas
Erysipelas is a disease of the very ________ , the ________, the ________,
and those with ________ or _______ ——- ulcers.
young, the aged, the debilitated,
and those with lymphedema or chronic cutaneous ulcers.
Pathogenesis and Epidemiology of Erysipelas
(Women or Men?) outnumber (women or men?) , except for very (young or old?) patients, where (boys or girls?) are more commonly affected.
There is ____eased frequency during the warmer/hot months and most cases are isolated.
Women
Men; young
Boys
incr
Most cases of erysipelas are caused by infection with group ____ streptococci and less often by group _____________
S. aureus, Pneumococcus species, Klebsiella pneumoniae, Yersinia enterocolitica, and Haemophilus influenzae type b have been known to cause an erysipelas-like infection
A
G, B, C or D.
Clinical Features of erysipelas
The classic lesion of erysipelas, with its well-defined margins, involves the _________ .
Nowadays, however, the _________ is the most common location.
After an incubation period of _________, there is an abrupt onset of fever, chills, malaise and nausea.
A few hours to a day later, a (small or large?) plaque of _________ develops that progressively spreads
face ; lower extremity
2 to 5 days
a small plaque of erythema
Clinical Features of erysipelas
The area is clearly demarcated from uninvolved tissue, hot, tense and indurated with _____________.
The affected area is painful to ________ and maybe ________ to touch
. Regional ________ is normally present.
________, ________, ________ and small areas of ________ may also form.
non-pitting edema.
palpation ; warm
lymphadenopathy
.
Pustules, vesicles, bullae and small areas of hemorrhagic necrosis .
Complications of erysipelas are (common or rare?) and usually occur in patients with ____________.
When the infection resolves, _______ and postinflammatory _______ changes may occur.
rare ; underlying disease.
desquamation
pigmentary
Diagnosis and Differential diagnosis of erysipelas
Diagnosis is based primarily on ________
Routine laboratory evaluation will show an elevated _________with a (left or right?) shift.
Blood cultures are positive in only about __% of cases.
_____ from local ports of entry, pustules or bullae, the _____, and the _____ are helpful.
clinical findings.; leukocyte count
Left ; 5; Swabs
Throat, nares
Diagnosis and Differential diagnosis of erysipelas
Culture of _______ biopsy specimens and the injection-_______ method yield poor results, especially in immunocompetent host
. Anti- _______ and ______ titers are good indicators of streptococcal infections.
Direct ________ and —————- tests can be used to detect streptococci within skin specimens.
skin ; re- aspiration
DNase B and ASO
immunofluorescence and latex agglutination
Differential Diagnosis of erysipelas
________ and other soft tissue infections (e.g. ________, ________ ________) as well as inflammatory causes of ‘_______________’ (e.g. ________ syndrome, contact ________)
cellulitis
erysipeloid, necrotizing fasciitis.
‘pseudocellulitis’
. Sweet’s syndrome
dermatitis
Treatment of erysipelas
A 10–14-day course of _______ is the treatment of choice for erysipelas caused by _______.
Although macrolides such as _______ may be used in _______ patients, there has been an increase in ________ among certain strains of Str. pyogenes.
Hospital admission and intravenous or intramuscular antibiotics should be reserved for _______ and ________ patients.
penicillin ; streptococci.
erythromycin ; penicillin-allergic
macrolide resistance
children and debilitated patients.
cellulitis
Cellulitis is an infection of the (superficial or deep?) dermis and ______ caused most commonly by _______ and ______
Deep dermis
subcutaneous tissue
Str. pyogenes and S. aureus
Epidemiology and Pathogenesis
Cellulitis in immunocompetent adults is most often caused by ________ or ________.
The majority of cellulitis in childhood is caused by ________, and less commonly by ________ .
A mixture of Gram-________ cocci and Gram-________ aerobes and anaerobes is associated with cellulitis surrounding ________ and ____________
Str. pyogenes or S. aureus.
S. aureus ; H. influenzae
positive ;negative
diabetic ulcers and decubitus ulcers.
pathogenesis of cellulitis
Bacteria may gain access to the ________ via an ________ or a ________ route.
Usually, in immunocompetent patients, a _____________________ is responsible
dermis ; external ; hematogenous
a break in the skin barrier
Cellulitis
In immunocompromised patients, a __________ route is most common.
Recurrent bouts of cellulitis may be caused by damage to the __________ system (e.g. previous __________________, __________ harvest or prior episode of _______________)
blood borne route
lymphatic system
lymph node dissection
saphenous vein harvest
of acute cellulitis
Lymphedema, alcoholism, diabetes mellitus, intravenous drug abuse, and peripheral vascular disease all predispose to cellulitis.
T/F
T
Clinical features of cellulitis
Cellulitis is often preceded by systemic symptoms, such as fever, chills and malaise.
rubor (erythema), calor (warmth), dolor (pain), and tumor (swelling).
The lesion usually has (ill or well?)-defined, (palpable or non-palpable?) borders.
In severe infections, vesicles, bullae, pustules or necrotic tissue may be present.
Ill
Non-palpable
Clinical features of cellulitis
Ascending ______ and ________ lymph node involvement may occur.
Children usually have cellulitis of the _______ and ______ region, whereas in adults the _________ are most often affected
lymphangitis
regional
head and neck
extremities
Clinical features of cellulitis
In intravenous drug abusers, the ___________ are often involved.
Complications are (common or rare?) , but include ___________ (if caused by a ___________ strain of streptococci), ___________ and ___________ bacterial ___________.
Damage to ___________ can lead to recurrent cellulitis.
upper extremities ; rare
acute glomerulonephritis ; nephritogenic
lymphadenitis ; bacterial endocarditis.
lymphatic vessels
Diagnosis and differential
diagnosis of cellulitis
The diagnosis of cellulitis is usually ________ . The leukocyte count is usually ________ or ________
Blood cultures are almost always ________ in immunocompetent hosts.
An important exception is ________ cellulitis, where there is usually ________ leukocyte count with a (left or right ?) shift and ________ blood cultures.
In children and immunocompromised patients, atypical organisms are more common, and ________ and ________ may be appropriate
clinical ; normal
only slightly elevated ; negative
H. influenzae ; an increased
left ; positive
needle aspiration and skin biopsy
differential diagnosis of cellulitis
The differential diagnosis of lower extremity cellulitis includes _________________ and other inflammatory diseases, such as _________________, _________________, and _________________ (especially _________________).
deep vein thrombosis
stasis dermatitis
superficial thrombophlebitis
panniculitis
lipodermatosclerosis
Treatment of cellulitis
In most cases of cellulitis, treatment should be targeted against
_________ and _________.
Mild cases require a ___- day course of an _________ that has good Gram- _________ coverage.
Hospitalization and parenteral antibiotics should be reserved for patients who are seriously ill and those who have _________ cellulitis.
Str. pyogenes and S. aureus
10- ; oral antibiotic
Gram- positive
facial cellulitis.
Treatment of cellulitis
_________ or _______ ulcers complicated by cellulitis require ____________ coverage (e.g. piperacillin/tazobactam or, in penicillin-allergic patients, metronidazole plus ciprofloxacin).
Diabetic or decubitus ulcers
broad-spectrum coverage
Impetigo
Impetigo is a (common or rare?) , (mildly or highly?) contagious, (superficial or deep?) skin infection that primarily affects (children or adults?).
common
highly
superficial
children.
Impetigo
The condition presents in both ________ and _________ forms .
The primary pathogens in these forms of impetigo are _________ and, less commonly, _________ (_________).
both non-bullous and bullous forms .
Staphylococcus aureus
group A b-hemolytic Streptococcus (Streptococcus pyogenes).
Worldwide, ________ is the most common bacterial skin infection in children.
impetigo
Predisposing factors to impetigo include ______ temperature, ——- humidity, ____ hygiene, an ________ and skin ______.
warm
high
Poor
Atopic diathesis
trauma
Nasal, axillary, pharyngeal and/or perineal S. aureus colonization imparts an increased risk for developing impetigo
T/F
T
Pathogenesis
Non-bullous impetigo
Non-bullous impetigo (or ______ impetigo) is usually caused by ______ and, on occasion, ______.
Infection occurs at (minor or major?) sites of trauma (e.g. chickenpox, insect bite, abrasion, laceration, burn).
Trauma exposes ______ proteins which allow the bacteria to ______, ______ and establish infection
crusted ; S. aureus
Str. pyogenes.
minor
cutaneous
adhere, invade and establish infection
Pathogenesis: Bullous impetigo
The etiologic agent of bullous impetigo, _________ , elaborates several exfoliative toxins and bullous impetigo is considered a (localized or generalized?) form of staphylococcal _________ syndrome .
In both diseases, _________ formation is mediated by _________ binding to the _________ protein , _________ and cleaving its extracellular domain, thus leading to _________ within the _________ _________ layer.
S. aureus; exfoliative toxins
localized ; scalded skin syndrome .
blister ;exfoliative toxin
desmosomal ; desmoglein 1
acantholysis ; epidermal granular layer.
Bullous Impetigo
In contrast to non-bullous impetigo, lesions can occur on _______ .
Although the differential diagnosis for non-bullous and bullous impetigo is extensive, the history , physical examination and ———- tests can often establish the diagnosis.
intact skin
ancillary
TREATMENT of impetigo
Primary treatment involves _______ care, including cleansing , removal of _______, and application of _______.
For healthy patients with a few, isolated superficial lesions and no systemic symptoms , either _______ 2% _______ or _______ cream or ointment can be prescribed.
For patients with limited disease, there is evidence that these _______ medications are at least equally (if not more) effective than _______
Local wound ; crusts
wet dressings.
mupirocin ; ointment
fusidic acid ; topical medications
oral antibiotics
Majority of bacterial skin infection are caused by ______________________ species.
Staphylococcus and Streptococcus
Antibiotics are used _______ with consideration for _______ pattern
Gram negative coverage is indicated in ________ under ____years and patient with _________ or immunocompromised
emperically
resistance
children; 3yrs
diabetes
