W3D2

Question 1

fasciitis

Answer 1

inflammation of subcutaneous connective tissue that surrounds muscle, vessels, nerves

Question 2

myositis

Answer 2

inflammation of muscle and it’s associated tissues

Question 3

What causes fasciitis and myositis?

Answer 3

trauma

infection

rheumatologic process

Question 4

necrotizing soft tissue infections

Answer 4

rapidly progressing infection of subcutaneous tissue that spreads along tissue planes

causes death of fascia and their associated vessels and nerves

can cause severe systemic toxicity

Question 5

risk factors for necrotizing soft tissue infection

Answer 5

anything that suppresses immune system (diabetes, neutropenia, steroid use)

peripheral vascular disease (b/c lack robust blood supply to affected tissues)

breaks in skin (IV drug use, burns, recent surgery)

exposure to fresh or brackish water

Question 6

early clinical presentation of necrotizing soft tissue

Answer 6

pain out of proportion to exam

warmth

erythema (redenning of the skin)

Question 7

crepitus

Answer 7

air in the subcutaneous tissue

may happen during infection, b/c organisms that infected may produce gas

Question 8

Type 1 necrotizing disease

Answer 8

polymicrobial infection

aerobes + anaerobes, often from GI or GU tract and oral flora (clostridum perfringens, bacteroide species, other coliform bacteria0

grey discharge (“dishwater fluid”), foul odor, crepitus

Question 9

Type 2 necrotizing disease

Answer 9

monomicrobial infection

most common: Group A strep (strep pyogenes)

many develop Strep toxic shock syndrome

often have recent blunt trauma

Question 10

necrotizing disease from staph aureus

Answer 10

previously rare, but increasingly common cause of necrotizing soft tissue

includes community-acquired MRSA infection

if in combo with others: type 1

if just staph a: type 2

Question 11

necrotizing disease from Vibrio and Aeromonas species

Answer 11

associated w/ recent history of water exposure

Question 12

Why do we use clindamycin for necrotizing disease involving staph or strep?

Answer 12

w/ “Eagle effect”, bacteria downregulate their production of penicillin binding protein, so penicillin can’t bind as much anymore

clindamycin isn’t hampered by “Eagle effect” - bind to 50s ribosome subunit of bacteria

reduce bacterial protein synthesis (and therefore reduce toxin released by bacteria)

Question 13

purulent skin infections

Answer 13

bacterial infection of the skin leading to collections of pus within the epidermis, dermis, or deeper skin tissue

most often staph aureus

Question 14

folliculitis

Answer 14

infection or inflammation of hair follicles

most often from staph aureus

Question 15

diagnosis and treatment of folliculitis

Answer 15

clinical diagnosis

supportive measures (apply warm compresses, avoid shaving, use antibacterial saps)

maybe topical antibiotics

if topical ineffective (or extensive disease, or sensitive area affected like face/genitalia): oral antibiotics

Question 16

abscess

Answer 16

collection of purulent matter (pus), usually in dermis and subcutaneous tissue

Question 17

furuncle (“boil”)

Answer 17

dermal abscess associated w/ hair follicles

most common on warm, moist skin (groin, neck, armpit, thighs, butt)

extends down into the dermis and subcutaneous tissue, forming a firm, tender nodule that progresses to an abscess there

Question 18

carbuncle

Answer 18

interconnecting subcutaneous abscess cavities (lots of furuncles), w/ draining tracts to the skin surface (sinus tracts)

Question 19

diagnosis and treatment of abscesses and furuncles

Answer 19

clinical diagnosis

if small: warm compresses

if larger: surgical incision and drainage

if severe infection: drainage, obtain culture and find treat w/ appropriate antibiotic

Question 20

pros and cons of using trimethoprim/sulfamethoxazole for MRSA infection

Answer 20

pros: generally well tolerated
cons: doesn’t have reliable coverage against Strep species, can cause elevated levels of potassium in pts w/ kidney disease

Question 21

pros and cons of using doxycyciline for MRSA infection

Answer 21

pros: generally well tolerated
cons: doesn’t have reliable coverage against strep, there is increasing drug resistance to doxy, side effect of photosensitivity, leads to teeth discoloration in kids

Question 22

pros and cons of using minocycline for MRSA infection

Answer 22

pros: MRSA tends to have less resistance to minocycline (compared to doxy)
cons: more GI side effects, causes teeth discoloration in kids

Question 23

pros and cons of using clindamycin for MRSA infection

Answer 23

pros: can reliably cover strep species in addition to MRSA
cons: MRSA resistance to clindamycin increasing, has some GI side effects, associated w/ causing c. difficile diarrhea

Question 24

impetigo

Answer 24

bacterial infection of the superficial epidermis, caused by staph aureus and strep pyogenes

one of most common bacterial infections of kids

close contacts often affected

may follow minor skin trauma

more common in hot, humid weather