Introduction to infectious diseases Flashcards
How do you treat pasteurella?
Augmentin
How do you diagnose necrotizing fasciitis?
MRI
describe the how you would call infections of the:
- epidermis
- dermis
- subcutaneous
epidermis=impetigo
dermis=erysipelas
subq=cellulitis
What are the most common causes of impetigo?
- S pyogenes
2. S. aureus
How would you treat impetigo?
dicloxacillin or cephalex. You’re worried about post-infectious glomerulonephritis.
- -Dicloxacillin for staph
- -Cephalex for strep
Treat erysipelas with
penicillin. It’s caused by group A strep
Cellulitis from fresh water
Aeromonas hydrophilia
Cellulitis from salt water
V vulnificus
Predisposing factors for cellulitis (5)
- trauma
- obesity
- edema (gravity dependent)
- impaired lymphatic drainage
- tinea pedis
How do you diagnose cellulitis?
Usually clinical
- -blood cultures rarely positive
- -aspiration has lots of false positives
- -punch biopsy usually not positive
What causes recurrent cellulitis?
Venous obstruction or lymphatic blockage
–Tx: oral penicillin
How do you treat folliculitis?
Usually S. aureus.
- -Treat with polymyxin B/neomycin/bacitracin
- -also mupirocin ointment
Describe three bugs that can cause ulcers
- sporotrichosis
- myobacterium marinum
- anthrax
Describe the typical pt with sporotrichosis
Gardeners/farmers present with a painless pustule/nodule.
What type of organism is sporotrichosis?
It’s a fungus.
Describe the typical pt with mycobacterium marinum
A person who works with aquarium or other fresh water areas. Will present with an ulcerating papule
Describe the typical patient with anthrax
A wool hide tanner comes in with a painless papule and also an ESCHAR (local black, necrotic lesion)
What does anthrax look like on gram stain?
Gram positive, large, rod
“puncture wound through sneaker” makes you think of what bug?
pseudomonas
What bugs come up in infected human bites?
- staph/strep
- eikenella corrodens
- fusobacteria
- prevotella
What do you use to treat infected human bites?
IV ampicillin and sulbactam (unasyn)
How do you decide what dose is high enough?
Give 4 x MIC
When would it be ok or not ok to prescribe someone with a penicillin allergy a cephalosporin?
If anaphylaxis with penicillin, then do NOT use a cephalosporin
What does clindamycin cover?
Gram positives and anaerobes
What kind of coverage do aminoglycosides provide?
Gram -
which drugs cover anaerobes?
metronidazole, clindamycin, and Beta-lactams with beta-lactamase inhibitors
