Infections Flashcards
(32 cards)
Enterococcus faecalis
GramPos Diplococcus (can look like Strep!)
NEC, Sepsis, UTI in child with GU abnormality
Tx: Vanc, amp, linezolid. Rifampin, quinolones
NOT clinda or cephalosporin
Listeria monocytogenes
GramPos diphtheroid (ROD)
Neonatal sepsis/infection
Nodules on the placenta, mild maternal fever/sx
Tx: Ampicillin covers Listeria, GBS, and Enterococcus. (Note: Gentamicin covers other GramNegs.)
Clostridium
GramPos, anaerobe
C. tetani
C. botulinum
Tx: Metronidazole or PCN, supportive care, anti-Ig
Corynebacterium diphtheria
GramPos Rod (histo might look like hyphae) Diptheria = low fever, URI sx -> pseudomembrane on tonsils/pharynx, airway edema, neuro sx (GBS) Tx: Metronidazole or erythromycin
Group A Strep (GAS)
GramPos Cocci in Pairs and Chains (Blue on Gram stain)
Group A (GAS) classic ex is Strep pyogenes
-GAS -> S for skin and oral abScesses
-Also P for pyogenes and pharyngitis (w/o viral sx)
-Scarlet fever, rheumatic fever, post Strep glomerulonephritis (PSGN)
-Strep Toxic shock syndrome (+/- necrotiz fasciitis)
Tx for pharyngitis: Ampicillin, PCN. If allergic, erythromycin or clinda.
MUST TX to prevent rheumatic fever (caused by GAS pharyngitis only)
But Tx does NOT prevent PSGN (caused by GAS pharyngitis or skin infection)
Tx for bad infection: IV -> PO
Alpha Hemolytic Strep
Silly pneumonic: Green Alf doing moon walk Strep viridans Strep pneumoniae (aka Pneumococcus)
Beta Hemolytic Strep
GBS (agalactiae) and Strep pyogenes
Pneumonic: aBpA (note lower and upper case order)
algalactiae group B, and remember B for baby
pyogenes group A, and remember GAS, S for skin
Group B Strep (GBS) - descrip/features and example
GramPos Cocci in Pairs and Chains (Blue on Gram stain)
Group B classic ex is GBS/agalactiae (B for baby)
Other Strep (non Group A, non Group B, non Strep pneumo)
GramPos Cocci in Pairs and Chains (Blue on Gram stain)
Strep viridans, mutans, and bovis
-Endocarditis: viridans»_space; mutans or bovis
Young child with fever, LAD, dysphagia/drooling, and
HYPEREXTENSION OF THE NECK
Retropharyngeal abscess (from GAS) Hyperextension likely pulls the posterior abscess away from the airway and helps open the airway
Young child with drooling and
LEANING FORWARD POSTURE
Epiglottis
Leaning forward allows epiglottis to be displaced anteriorly, keeping airway open
Young child with drooling, trismus, deviated uvula, unilateral tonsilar swelling, and “hot potato voice”
Peritonsillar abscess (from GAS +/- anaerobes) Tx: IV (ex. Clinda, ampicillin/sulbactam) -> PO (amox/clav)
Scarlet fever
Group A Strep (GAS)
Painless, sandpaper -> erythematous rash
Pastia’s lines (lines near creases)
Perioral pallor and strawberry or white tongue
Strep pneumoniae
GramPos diplococci. ENCAPSULATED!
aka Pneumococcus
-Most common cause of pneumonia in kids
-Most common cause of occult bacteremia (no need to tx if no symptoms)
-Common cause of meningitis, osteomyelitis, septic arthritis, sinusitis, otitis media, (endocarditis?), peritonitis
-Rare cause of cellulitis or brain abscess
Group B Strep
Neonatal Sepsis
Early: w/i first 3 DOL. Usually pneumonia
Late: after first 3 DOL - 90 DOL. Often focal, such as meningitis, cellulitis, osteomyelitis.
Tx: PCN G!
Group B Strep
Screening and Prophylaxis
GBS screen: 35-37 weeks gestation
Tx: PCN at least 4h prior to delivery. Monitor baby x 48h.
If Mom not treated but should have been, get CBC and blood culture on baby.
No tx for C/S with intact membranes (even if + indications)
Indications:
-Any evidence of GBS during current pregnancy
-Unknown GBS status plus PREM, PROM, fever, or NAAT (rapid nucleic acid amplification test positive)
-Mom had prior baby with GBS disease (but not just if Mom had GBS UTI or positive test in past pregnancy)
Staphylococcus aureus
GramPos in clusters. Coagulase positive. Can be MRSA.
- Purulent skin infections, toxic shock syndrome, sinusitis.
- Most common cause of osteomyelitis. More common cause of septic arthritis than Strep pneumo.
- If growing in blood, MUST tx with IV abx and get ECHO to evaluate for Staph aureus endocarditis
- Tx skin infections: Clinda or Bactrim are first-line
- Tx serious infection: Vancomycin or linezolid
CONS: Coag negative Staph
Staph epidermidis. Can be MRSE.
Often extremely resistant to abx.
-If growing in blood, TREAT and TREAT BIG with Vancomycin. (Ignore residency training for purpose of boards) Might come back MRSA eventually.
-Secondary bacterial peritonitis in patient on dialysis - assume MRSE, tx with Vanc
-VP shunt meningitis - assume MRSE, tx with Vanc
Strep vs Staph skin infections
Either can cause any, but in general:
Strep: cellulitis, necrotiz fasciitis, impetigo (more common than Staph, but usually not bullous), erysipelas (fever + cellulitis). Rash is usually erythematous and painful.
Staph: Purulent skin infections, carbuncles/furuncles (if <5cm, I&D, if >5cm give clinda or Bactrim), bullous impetigo (with VERY thin blisters), folliculitis, breast abscess (give the neonate IV abx)
Recurrent abscesses, failure to thrive, Serratia in a boy
Chronic granulomatous disease (granulomatuX)
- X-linked recessive (boys are affected). Present by 5yo
- Serratia, fungi (Aspergillus, candida), E coli, Staph = catalase positive organisms
- Not a cell line issue (cell counts normal) but a neutrophil function issue (poor nitro oxidative burst)
- Low grade, recurrent infections: abscesses (skin, liver), osteo, lymphadenitis, skin infections, GI infections, granulomas
- Dx: Nitroblue Tetrazolium (“neutrophil blue”) or Dihydrorhodamine Fluorescence test
- Tx: PCP prophy, other prophy
Recurrent bacterial infections (PNA, skin), aphthous stomatitis, foul smelling greasy stools, poor weight gain
Shwachman-Diamond Syndrome
- Autosomal recessive
- Bone marrow failure/aplasia (pancytopenia, neutropenia, low Ig levels) and neutrophil defects
- Pancreatic insufficiency (can look like cystic fibrosis but electrolytes and lungs are normal)
- Bone/skeletal abnormalities
- Can have renal or liver abnormalities
Baby with severe macrocytic anemic, triphalangeal thumbs, and cleft palate
Diamond-Blackfan Anemia
- Pure red cell aplasia (only the red cell line is affected)
- Severe macrocytic anemia with low retic counts but no signs of hemolysis (i.e. no icterus/jaundice or increase bilirubin). Presents before 3 mos of age.
- Mnemonic: standing fan with three large black fan blades shaped like RBCs
Frequent skin and lung infections, oculocutaneous albinism, neutropenia, normal lymphocyte count
Chediak-Higashi Syndrome
- Autosomal recessive
- Neutropenia and poor neutrophil chemotaxis
- Neutrophils contain giant lysosomal granules
- Platelet dysfunction
- Oculocutaneous albinism (hig-“ashy skin”)
- Frequent skin and lung infections with Staph and Strep
6 mos old baby with frequent otitis media, skin and sinopulm infections with neutropenia and lymphocytosis
Hyper-IgM syndrome
- IgM to IgG class switch cannot occur due to missing signal from T cell problem
- Lymph nodes and tonsils ARE present
- Neutropenia and lymphocytosis
- Opportunistic infections, including PCP, and risk of lymphoma/cancer
- Diarrhea
- Tx: IVIg and Bactrim
