Pyogenic skin infections

Question 1

Infection of subq tissue with draining sinuses that is endogenous from mucus membrane that may present with lock jaw

Answer 1

Actinomycosis

Question 2

Gram positive cocci arranged in clusters with positive catalase and coagulase tests

Answer 2

S aureus

Question 3

Staphs with negative coagulase test

Answer 3

S epidermidis
S saprophyticus

Question 4

Most common cause of localized pyogenic cutaneous infections

Answer 4

S aureus

Question 5

Causes of impetigo

Answer 5

Streptococcus pyogenes
S aureus

Question 6

Erythematous macule, vesicle, and pustule with ruptures leaving honey-colored crusts with lymphadenitis

Answer 6

Non-bullous impetigo

Question 7

Superficial fragile serum-filled bullae on trunk and extremities

Answer 7

Bullous impetigo

Question 8

Rapidly growing, gram-positive cocci in chains with beta-hemolytic colonies on blood agar

Answer 8

Streptococcus pyogenes

Question 9

Positive bacitracin test of blood agar and negative catalase test

Answer 9

Streptococcus pyogenes

Question 10

Complications of streptococcal pyogenes infection in a person with soft tissue infection

Answer 10

Streptococcal toxic shock syndrome

Question 11

Complications in pts with prior streptococcal pharyngitis

Answer 11

Rheumatic fever
Glomerulonephritis

Question 12

Exotoxins A and C of streptococcus pyogenes are related to what presentation

Answer 12

Scarlet fever

Question 13

Exotoxin B of streptococcus pyogenes is related to what presentation

Answer 13

Necrotizing fasciitis

Question 14

Hyaluronidase streptokinase produced by streptococcus pyogenes is related to what presentations

Answer 14

Erysipelas
Cellulitis

Question 15

Key virulence factor of streptococcus pyogenes

Answer 15

M protein

Question 16

Well demarcated, salmon red rash with pain, edema and erythema that is commonly on the legs

Answer 16

Erysipelas

Question 17

Systemic manifestations in Erysipelas

Answer 17

Leukocytosis and lymphadenopathy
Chills and fever

Question 18

Progression of erysipelas

Answer 18

Sepsis
Local necrosis of skin

Question 19

Pathogens that cause cellulitis

Answer 19

S pyogenes
S aureus
Clostridium perfringens
Erysipelothrix rhusiopathiae
Vibrio vulnificus
Pasteurella mutocida
Pseudomonas

Question 20

Main virulence factor of Clostridium perfringens

Answer 20

Alpha toxin/lecithinase

Question 21

Effect of alpha toxin of Clostridium perfringens

Answer 21

Hemolytic, cytotoxic, and necrotic by degrading lecithin

Question 22

Gram positive rods in pus without any inflammatory cells due to lysis

Answer 22

Clostridium perfringens

Question 23

Treatment for gas gangrene

Answer 23

Penicillin
Clindamycin
Debridement
Amputation

Question 24

Test for alpha toxin of Clostridium perfringens

Answer 24

Nagler reaction

Question 25

Contaminates wounds caused during fishing, whaling, butchering, and in veterinarians

Answer 25

Erysipelothrix rhusiopathiae

Question 26

Gram positive, filamentous, catalase negative bacilli

Answer 26

Erysipelothrix rhusiopathiae

Question 27

Viral factors and their functions in Erysipelothrix rhusiopathiae

Answer 27

Neuraminadase --> penetrates epithelial cells Capsule --> antiphagocytic

Question 28

Erythematous violaceous rash on finger that proceeds to cellulitis and can lead to erysipeloid and septicemia

Answer 28

Cellulitis from Erysipelothrix rhusiopathiae

Question 29

Treatment for Erysipelothrix rhusiopathiae cellulitis

Answer 29

Penicillin Cephalosporins Clindamycin Fluoroquiniolones

Question 30

Gram negative, curved rods. Oxidase positive and halophilic.

Answer 30

Vibrio vulnificus

Question 31

Transmission of Vibrio vulnificus

Answer 31

Contact with marine shellfish

Question 32

Symptoms of Vibrio vulnificus infection

Answer 32

Ecchymosis Painful bullae Cellulitis Septicemia

Question 33

Treatment for Vibrio vulnificus infection

Answer 33

Tetraclycin Cefotaxime Fluoroquinolones Debdridement

Question 34

Gram negative rods. Green pigmented colonies with fruity odor on culture. Oxidase positive.

Answer 34

Pseudomonas aeruginosa

Question 35

Virulence factors of pseudomonas aeruginosa

Answer 35

Elastases Exotoxin Endotoxin Capsule Slime layer

Question 36

Pathogen causing erythematous centrally necrotic lesions that rapidly progresses to sepsis and direct invasion and destruction of blood vessels

Answer 36

Pseudomonas aeruginosa

Question 37

Ecthyma gangrenosum

Answer 37

Skin lesion with central necrosis and erythematous margins

Question 38

Treatment of Pseudomonas aeruginosa infections

Answer 38

Cephalosporins Carbapenems

Question 39

Pharyngitis, strawberry tongue, flushed face, oral pallor, diffuse blanching rash

Answer 39

Scarlet fever after streptococcus pharyngitis

Question 40

Rash with separation of epidermis diffusely due to loss of adhesion in young children

Answer 40

Staphylococcal scalded skin syndrome (SSSS)

Question 41

Acute onset of fever, hypotension and multi-organ dysfunction with diffuse macular desquamating erythematous rash

Answer 41

Toxic shock syndrome

Question 42

Virulence factor implicated in scalded skin syndrome

Answer 42

Exfoliative toxin