Skin & Soft Tissue Infections

Question 1

What organism is usually responsible for “hot tub” folliculitis?

Answer 1

-Pseudomonas aeruginosa

Question 2

<p>What kind of infection are patients who have undergone saphenous vein harvesting?</p>

Answer 2

<p>Cellulitis/Erysipelas with venous &amp; lymphatic compromise</p>

<p>-Streptococcus</p>

Question 3

What organism is usually responsible for lymphangitis?

Answer 3

-S. Pyogenes

Question 4

<p>What two organisms are usually responsible for cat scratch infections?</p>

Answer 4

<p>-Strep pyogenes</p>

<p>-Pasturella multocida</p>

Question 5

<p>What is included in the differential dx of a rapidly progressive necrotizing soft tissue infection?</p>

Answer 5

<p>-Group A streptococci (S. pyogenes);</p>

<p>-Vibrio species;</p>

<p>-Aeromonas species;</p>

<p>-Clostridium species;</p>

<p>-Rarely, Staphylococcus aureus (CA-MRSA)</p>

Question 6

<p>Clostridial myonecrosis denotes invasion of \_\_\_\_\_\_\_\_\_\_\_\_ (even spontaneously) by C. perfringens, C. novyi or C. septicum.</p>

Answer 6

<p>healthy muscle</p>

<p>**C. septicum is frequently associated with underlying systemic malignancy (e.g., colon cancer).</p>

Question 7

<p>What is the Therapy of Clostridial Gangrene/Myonecrosis?</p>

Answer 7

<p>Therapy includes immediate aggressive surgical debridement/amputation &amp; high dose penicillin</p>

<p>-add clindamycin to decrease toxin production</p>

Question 8

<p>What is the Therapy of Life-Threatening Group A Streptococcal Infections, ie Toxic shock syndrome?</p>

Answer 8

<p>-Aggressive surgical debridement or amputation is frequently needed.</p>

<p>-?? Hyperbaric oxygen (if it is available).</p>

<p>-Intravenous immunoglobulin has been shown to be of some theoretical benefit in 2 trials:</p>

Question 9

Who is more susceptible to necrotizing soft tissue infections due to Vibrio species?

Answer 9

-Individuals compromised by cirrhosis, AIDS, or malignancy

Question 10

<p>Rapidly progressive cellulitis or necrotizing fasciitis due to \_\_\_\_\_\_\_\_\_\_\_occurs in the setting of an injury related to fresh water exposure. The syndrome that results may be identical to that produced by Vibrio species.</p>

Answer 10

<p>Aeromonas hydrophila</p>

<p>*also think medicinal leeches</p>

Question 11

<p>What is fournier's gangrene?</p>

Answer 11

<p>-Necrotizing perineal infections,that occur most frequently in diabetics and patients with granulocytopenia</p>

<p>-Microbiology reflects mixed bowel flora</p>

Question 12

<p>What is Meleney's gangrene?</p>

Answer 12

<p>-Post-surgical mixed infection;</p>

<p>-Microbiology reflects site of surgery (e.g., intra-abdominal flora).</p>

Question 13

<p>What is Ludwig's angina?</p>

Answer 13

<p>-Polymicrobial infection of submandibular &amp; submental spaces;</p>

<p>-Bacteriology reflects complex oral flora.</p>

Question 14

Only_______of Foot Infections in Diabetics is Due to Vascular Disease/

Answer 14

15%

Question 15

________ of Foot Infections in Diabetics is Due to Neuropathy

Answer 15

85%

Question 16

<p>The most common pathophysiologic process leading to diabetic foot infections is:</p>

<p>a. Peripheral vascular disease</p>

<p>b. Hyperglycemia</p>

<p>c. Neuropathy</p>

<p>d. Depressed neutrophil function</p>

Answer 16

<p>c. Neuropathy</p>

Question 17

<p>Your roommate was celebrating his 21st birthday, injudiciously as it turns out, and lost all of his inhibitions due to alcohol. He happened to provoke a fight with a big guy in the bar and punched him in the mouth. 28 hours later, his right hand began to swell at the 2nd &amp; 3rd metacarpal-phalangeal joints over some lacerations that he suffered. The bacteriology most likely includes:</p>

<p>a. Enterococcus faecalis</p>

<p>b. Streptococcus iniae</p>

<p>c. Pseudomonas aeruginosa</p>

<p>d. Anaerobic organisms (Veilonella, Peptostreptococcus, Fusobacterium)</p>

Answer 17

<p>d. Anaerobic organisms (Veilonella, Peptostreptococcus, Fusobacterium) =Clenched fist injury</p>

Question 18

<p>36 hours ago, while trying to pet it, your neighbor’s cat bit you on the hand. Your index finger is now swollen &amp; tender. The bacteriology likely includes:</p>

<p>a. Streptococcus zooepidemicus</p>

<p>b. Enterococcus faecium</p>

<p>c. Pseudomonas aeruginosa</p>

<p>d. Pasteurella multocida</p>

Answer 18

<p>d. Pasteurella multocida</p>

Question 19

<p>The hand surgeons consulted you to help with management of an infection in a 34-year-old man who had amputated his right index finger in a snow blower 5 days ago. They reattached his finger, but it is now red, tender and swollen and a culture is growing an aerobic, gram-negative rod. You suspect the infection was caused by:</p>

<p>A. Pseudomonas aeruginosa that contaminated the snow blower blades.</p>

<p>B. Nosocomial Klebsiella pneumoniae infection.</p>

<p>C. Aeromonas hydrophila from medicinal leaches used to maintain blood vessel patency.</p>

<p>D. Fusobacterium from his mouth</p>

Answer 19

<p>C. Aeromonas hydrophila from medicinal leaches used to maintain blood vessel patency.</p>

Question 20

<p>This 28-year-old man returned last night from a 4-day ski trip in Aspen. Yesterday, he began to develop this rash confined to his chest &amp; below. He spent a lot of time drinking beer in the hot tub. It is likely caused by:</p>

<p>a. Streptococcus pyogenes</p>

<p>b. Staphylococcus epidermidis</p>

<p>c. Streptococcus iniae</p>

<p>d. Pseudomonas aeruginosa</p>

Answer 20

<p>d. Pseudomonas aeruginos</p>

Question 21

<p>24 hours ago, while trying to unhook this fish from his line, a 42-year-old cirrhotic Gulf fisherman stepped on the dorsal fin which penetrated his foot. Now, he presents with a rapidly progressive necrotizing cellulitis of the foot and leg. The most likely organism causing this is:</p>

<p>A. Streptococcus pyogenes</p>

<p>B. Aeromonas hydrophila</p>

<p>C. Vibrio vulnificus</p>

<p>D. Pseudomonas aeruginosa</p>

Answer 21

<p>C. Vibrio vulnificus Salt Water*</p>

Question 22

<p>The hand surgeons biopsied this abnormal bone 2 days ago; the culture is growing Eikenella corrodens. This likely resulted from:</p>

<p>A. Penetration from a fishing hook</p>

<p>B. A dog bite</p>

<p>C. Human bite/saliva contamination</p>

<p>D. Bacteremic spread from endocarditis</p>

Answer 22

<p>C. Human bite/saliva contamination</p>

Question 23

<p>This 72-year-old man presented with pain in the left arm. On examination, it feels to you like Rice Krispies. Gram stain shows no neutrophils. What is the organism?</p>

<p>A. Streptococcus anginosus</p>

<p>B. Pseudomonas aeruginosa</p>

<p>C. Clostridium septicum</p>

<p>D. Aeromonas hydrophila</p>

Answer 23

<p>C. Clostridium septicum</p>

Question 24

<p>While feeding this squirrel in Hermann Park, your girlfriend was bitten on the finger. Management should include:</p>

<p>A. Tetanus immunization</p>

<p>B. Rabies immunization</p>

<p>C. Prophylactic azithromycin</p>

<p>D. Both a &amp; b</p>

Answer 24

<p>A. Tetanus immunization</p>

Question 25

<p>A patient with a necrotizing ulcer on his scrotum likely has underlying:</p>

<p>A. Burn</p>

<p>B. Diabetes mellitus</p>

<p>C. Zipper trauma</p>

<p>D. Hidradenitis suppurativa</p>

Answer 25

<p>B. Diabetes mellitus</p>

Question 26

<p>This 25-year-old man injured his leg while waterskiing in Lake Conroe. There are hemorrhagic bullae. The causative organism is likely to be:</p>

<p>A. Aeromonas hydrophila</p>

<p>B. Vibrio vulnificus</p>

<p>C. Streptococcus pyogenes</p>

<p>D. Staphylococcus aureus</p>

Answer 26

<p>A. Aeromonas hydrophila</p>

<p></p>

<p>**FRESH WATER</p>