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53 Cards in this Set
- Front
- Back
Major portals of entry for Strep infections
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Upper respiratory tract, skin
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3 delayed sequelae of GABHS
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scarlet fever, rheumatic hart disease, glomerulonephritis
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what 2 conditions can follow strep pharyngitis
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Scarlet fever, rheumatic heart disease
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What type of infection does post strep glomerulonephritis follow
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strep skin infections
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Impetigo
a. what layers does it infect b. transmission c. 2 causative organisms d. course |
a. superficial - epidermis
b. direct contact, transmisson from individuals, arthropods c. staph and strep d. purulent --> resolves on its own |
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Patient has multiple thick-crusted, golden-yellow lesions or pustules that develop within 10-14 days on lower extremities, face and scalp
2 organisms that cause this? what layers are implicated? treat? |
impetigo
staph or strep epidermis/dermis bacitracin (GABHS), retapamulin (strep and staph) |
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Serotype implicated in invasive GABHS disease
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M1 and M3
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What is erysipelas?
2 types? course? |
acute inflammation of skin with involvement of cutaneous lymphatics --> advancing raised, well-demarcated margins
facial (precedes sore throat) trunk (surgical or trauma) facial resolves on its own, trunk lesions progress |
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Cellulitis
what layer is implicated? where does it infect? |
lower dermis
sites of burn, wound, or surgery |
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How do you know if cellulitis has progressed to lymphangiitis?
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appears as a linear red streak that spreads from distal to proximal along lymph pathway
accompanied by swelling, tenderness, redness, pain, swelling of LNs |
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2 ways in which cellulitis is different from erysipelas
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1. lesion of cellulitis is not raised
2. cellulitis has indistinct borders |
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Treatment for strep infections
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IV penicillin
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Layers implicated in necrotizing faciitis and myositis
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deeper subcutaneous tissues and fascia
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patient has
-high fever and toxicity -extreme prostration (pain out of proportion to exam) -rapidly spreading inflammatory process with bullae (yellow liquid) dx? treat? |
necrotizing fasciitis
surgical debridement, antibiotics |
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How does one often acquire myositis?
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penetrating trauma into muscle
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Strep toxic shock syndrome
a. how is it acquired b. how does it spread c. symptoms |
a. infected wound
b. bacteremia --> superantigen toxin, often infects muscle c. fever, rash, shock, myositis |
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how strep toxic shock different from staph toxic shock?
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strep = bacteremia
staph = no bacteremia (toxin enters blood stream), less fatality |
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Patient comes in with
-fever, pain in extremities -tachycardia, hypotension -necrotizing fasciitis -confusion, coma |
strep toxic shock syndrome
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Treatment for Strep toxic shock
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-Pen G
-first gen cephalosporin or vancomycin -clindamycin (Eagle effect = kills bact in stationary phase, also inhibits toxin production) |
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What are superantigens
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toxins that bridge the TCR and the APC --> massive cytokine release, lymphocytes activated --> fever, shock hypotension
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2 superantigens produced by GABHS
secreted protease that contributes to tissue destruction |
SpeA and SpeC
SpeB |
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types of clostridium
a. resident in soil, causes gangrene b. colonizes intestine of animals c. associated with necrotizing enterocolitis |
a. A
b. B to E c. C |
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Most prominent clostridium toxin
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Alpha = lethal toxin
Phospholipase C --> disrupts cell membranes, hemolysin, increases vascular permeability by killing endothelial cells, causes necrosis |
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What does c. perfringens cause
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cellulitis --> necrotizing fasciitis, suppurative myositis, myonecrsis
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What is suppurative myositis
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abscesses in muscle without necrosis of muscle, lacks systemic toxicity
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In clostridial myonecrosis, why is there a lack of inflammatory cells
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toxins lyse the WBCs entering the tissue
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what is the general term for superficial purulent infections of the skin
2 types |
pyoderma
prmary = healthy skin secondary = superinfection of skin previously affected by trauma or chornic skin disorder |
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Subtypes of pyoderma
Thin vesicles and blisters with honey-colored crust that heal without leaving scars; these are contagious |
impetigo
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Subtypes of pyoderma
impetigo that extends deeper into epidermis; leaves scars when it heals |
ecthyma
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Lesion that looks like ecthyma, seen in immunocompromised individuals from pseudomonas
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ecthyma gangrenosum
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Subtypes of pyoderma
S. aureus spreads through dermis and subcutaneous tissue --> coalesce --> drain out of skin at several points |
carbuncle
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Subtypes of pyoderma
superficial skin infection that spreads to lymphatics -raised border, tender, well-demarcated -associated with diabetes, chronic venous inusufficiency, chronic lymphatic obstruction |
erysipelas (staph or GABHS)
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Subtypes of pyoderma
-tender, warm, red plaque -no raised border -systemic features of sepsis |
cellulitis
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Cause of cellulitis
perianal cellulitis in children -associated with acute glomerlonephritis |
streptococci
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Cause of cellulitis
-immunocompromised host -associated with ecthyma gangrenosum |
pseudomonas aeruginosa
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Cause of cellulitis
injuries in fresh water |
aeromonas hydrophila
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Cause of cellulitis
Salt water injuries or ingestion of raw seafood Diabetics and cirrhotics vulnerable, esp. liver disease |
vibrio vulnificus
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Cause of cellulitis
trauma from dirty wounds causes gas formation but minimal toxicity |
clostridium
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Cause of cellulitis
-food handlers, seafood -tender, red-purple plaques |
erysipelothrix rhusiopathiae
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Cause of cellulitis
-dog or cat bites -on hands and feet -rapidly progressive |
pasteurella multocida
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Cause of cellulitis
immunocompromised host |
crytococcus neoformans
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Necrotizing faciitis
what layers? |
SKIN, SUBCUTANEOUS TISSUE, DEEP FASCIAL PLANES
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Disease in which toxins secreted by bact cause tissue separation along fascial planes --> vascular thrombosis --> tissue ischemia --> infarction of superficial layers of skin
how do you treat? |
necrotiizing fasciitis
treat with surgery, hyperbaric oxygen |
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Types of necrotizing fasciitis
-mixed due to anaerobes, strep, staph, coliforms -painful, but w/o systemic involvement -subacute presentation; found in surgical wounds |
progressive bacterial synergistic gangrene
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Types of necrotizing fasciitis
-all layers of skin -rapid onset and extension -near GI or GU -painful lesions, septic -diabetics, obese, elderly what if it involves the scrotum |
necrotizing fasciitis type I (synergistic necrotizing cellulitis)
Fournier's gangrene |
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Types of necrotizing fasciitis
-Specific M-types of GABHS -can be after surgery or not -pain, swelling, spread, systemic toxicity -gas formation seen on xray treat? |
Type II (Streptococcal gangrene)
treat with penicillin and clindamycin |
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Types of necrotizing fasciitis
-monomicrobial (c. perfringens) -contamination of wounds by soil, feces, or site of tissue hypoxia -Death may occur in 24 hrs -gas in soft tissues, palpable on physical and radiographical exam dx? treat? |
necrotizing pyomyositis (clostridial myonecrosis)
penicillin + clindamycin |
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disease causes
-swollen, painful muscle, induration -progresses to point tenderness, fever, abscess -progresses to systemic illnes with bacteremia (fever, hypotension, sepsis) CT/MRI reveals abscessies dx? cause? how does it get in and spread? |
pyomyositis
staph aureus gets into muscle following blunt trauma, spreads hematogenously |
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2 things on differential if soft tissue infection is
-rapidly spreading -fever -hypotension -crepitation -bullae -discolored -severe pain |
necrtizing fasciitis or gas gangrene
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Classification of infection that is
-superficial -gram pos -no complicating medical illness treat? |
uncomplicated
treat with antibiotics only -vancomycin, daptomycin, and linezolid (for severe) -doxycycline, clindamycin, or TMP-SMX for less severe |
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Classification of infection that
-involves more than one layer -may involve abscesses -occurs in presence of immunocompromised or vascular insufficiency -polymicrobial treat? |
broader spectrum Abs, surgical
Complicated infections |
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4 indications for oral therapy
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-not systemically ill (no fever or leukocytosis)
-not immunocompromised -able to take orally -responsible enough to come back if things get worse |
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optimal duration of therapy
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1-2 weeks
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