Infectious Disease Flashcards

Question

Cellulitis sxs and dx

Answer 1

inflammation: erythema, warmth, swelling, pain +- fever clinical dx blood cultures if w fever tissue cx if w wound, ulcer, or site of infection imaging (plain film, MRI) if suspicion of deeper infection

Answer 2

base treatment on suspected pathogen from hx most require parenteral abx should cover group A strep and MSSA (oxacillin, cefazolin) MRSA only if suspected (vanc) Continue IV abx until signs of infection improve then oral abx for 2 weeks

Answer 3

Life-threatening infection of deep soft tissues that rapidly tracks along fascial planes. extension of infection > thrombosis of microcirculation > tissue necrosis, discoloration, crepitus, and cutaneous anesthesia. erythema & extreme pain out of proportion to PE → blue hemorrhagic bullae (blisters at site) → gangrene → septic shock +- crepitus. (Fournier gangrene - in the perineum +- scrotal involvement esp w impaired immunity (DM) after trauma to area.) lrinec score May rapidly progress to sepsis, toxic shock syndrome (TSS), multi-organ failure. Bug: s pyogenes, clostridium perfringens Rfx: recent surgery, diabetes, trauma, IVDU SXS: fever, pain out of proportion to appearance of skin in early stages > high index of suspicion TX: abx alone not sufficient, NEED RAPID SURGICAL EXPLORATION AND DEBRIDEMENT Broad spectrum parenteral abx tx (carbapenem or pip tazo + MRSA coverage eg vancomycin or daptomycin + clinda)

Answer 4

Common sources: UTIs, intra-abdominal infections like colitis or cholangitis, pneumonia, central venous catheters Bugs: E.coli, klebsiella pneumoniae, enterobacter spp, pseudomonas aeruginosa Rfx: immune compromise, presence of indwelling catheter, recent abx use, housing in long term care facility, healthcare contact Gram-negative pathogens a/w rapid systemic response due to endotoxin production endotoxin (lipopolysaccharide) comprises about 75% of the outer membrane of GNRs > potent inducer of host defense cells, leading to systemic inflammation: activation of proinflammatory mediators, hypotension, tissue damage, organ dysfunction, activation of coagulation cascade. High levels of proinflammatory cytokines, tumor necrosis factor, and vasodilators lead to apoptosis of endothelium cells in multiple organs, increased vascular permeability and hypotension hypoperfusion, manifesting as lactic acidosis, oliguria, and/or altered mental status alterations in temperature leukocytosis tachycardia tachypnea depressed ventricular ejection fraction

Answer 5

``` Klebsiella species Escherichia coli Enterobacter species Pseudomonas aeruginosa Haemophilus influenzae Acinetobacter species Neisseria meningitidis Proteus species Salmonella species Serratia species Brucella species Campylobacter species ```

Answer 6

SIRS; fever, rigors, sweats, tachycardia, tachypnea, hypotension, AMS Onset and shock may be rapid

Answer 7

Blood cultures Evaluation should include careful search for source of infection Obtain follow-up cultures at 48-96 hours to document response to treatment Most pathogens yield cx results within 48 hrs

Answer 8

empiric abx asap combination therapy when Pseudomonas or multi-drug resistant organism suspected remove, drain, or debride any potential sources of infection like vascular or urinary catheters, intra-abdominal abscesses, obstructive cholangitis duration of therapy varies with pathogen, adequacy of source control, and patient characteristics

Answer 9

``` pip-tazo cefepime, ceftazidime imipenem, meropenem aztreonam cipro, levofloxacin gentamicin, tobramycin, amikacin polymyxins ```

Answer 10

MC of bacteremia Result from breaches in skin; indwelling catheters, post surgery, local infection like pna or cellulitis Common complications > metastatic infections like endocarditis, embolization to CNS or other visceral organs, vertebral osteomyelitis, other bone/joint infections

Answer 11

Vary from asx to fever alone to sepsis

Answer 12

2 sets of blood cx collected before abx Evaluation should include a careful assessment for the source of infection, any potential removable foci of infection, such as an indwelling line, or metastatic sites of infection. Echo if suss for IE

Answer 13

Prompt source control and abx Removal and/or debridement of any source or metastatic focus of infection, such as drainable abscesses and indwelling foreign bodies MSSA: oxacillin, nafcillin, or cefazolin (if normal renal fxn) MRSA: vancomycin, daptomycin Minimum 14-day course can be considered in patients who defervesce and clear bacteremia within 72 hours, have no evidence of complications, and do not have indwelling catheters or prosthetic material, underlying malignancy, or immunocompromise. All others should be treated with 4-6 weeks of antibiotics.

Answer 14

path: t. pallidum 1: singular ulcer painless +LN non-tender 2: fever + rash targetoid palms/soles 3: neurosyphilis tabes dorsalis argyll robertson DX 1: darkfield microscopy 2: RPR > FTA-ABS 3: LP > CSF RPR > CSF FTA-ABS TX 1: PCN x 1 IM 2: PCN x 1 IM EL: PCN x 1 IM LL: PCN IM qwk x 3 wks 3: PCN IV q4h x 10-14 days

Answer 15

Lymphogranuloma venereum (LGV) is a sexually transmitted infection caused by a particular strain of chlamydia bacteria path: c trachomatis singular painless +LN tender suppurative, drainage DX: NAAT TX: doxy

Answer 16

path: h. ducreyi singular painful +LN tender dx: gram stain + cx tx: azithro or cipro

Answer 17

path: hsv1, hsv2, DRG painful burning prodrome painful vesicles on erythematous base coalesce = ulcer dx: pcr tx: acyclovir or valacyclovir