URT infections Flashcards
the common cold
rhinovirus vs. coronavirus
the most common agent of the common cold is..
rhinovirus THEN coronavirus
ddx allergic rhinitis
blue-colored nasal passages
clear, serous fluid-colored rhinorrhea
“nasal salute”
itchy, serous discharge conjunctivitis
ddx purulent rhinitis
lasts longer: 14 d (vs. 4-5)
thicker, denser rhinorrhea
caused by Hib
DO NOT USE ABX
coronavirus is enveloped, therefore
does not survive as long in the environment (no fomite transfer)
period of incubation is shorter in..
Rhinovirus (poss. hrs) vs coronavirus (3 days)
most important Ab for Rhinovirus* viral immunity is
IgA2 (but only short term immunity)
rhinovirus uses this as cell surface receptor
ICAM-1
is fever seen in rhinovirus or coronavirus?
rarely
other viral agents that cause infectious rhinitis
influenza v type C adenovirus RSV influenza v type A or B PIV hMPV other enteroviruses
bacterial infections that can cause rhinitis
Bordetella pertussis
Mycoplasma pneumoniae
Chlamydia pneumoniae
DO NOT want to use ASA in children bc
could cause Reye’s syndrome if influenza virus, VZV?
Moraxella catarrhalis
G-diplococci, kidney bean, non-encap, non-staining, Ox +
3rd most common cause of AOM
3rd: BAC cause of acute sinusitis
3rd: BAC cause of AE-CB or COPD/emphysema
imp. LRTI (tracheitis–>pneumonia)
viral agents of sinusitis
Rhinovirus
Influenza V
PIV
bac agents of sinusitis
Strep pneumonia
NTHi
Moraxella catarrhalis (N. or B.)
unique risk factor for sinusitis
Prim. ciliary dyskinesia (PCD) aka immotile ciliary syndrome or Kartagener syndrome (KS)
main pathogenic event
closure of sinus ostia
most common sinus of sinusitis
Maxillary, then ethmoid, frontal, sphenoid (MEFS)
fever with sinusitis?
may have low grade fever
purulent nasal discharge in sinusitis implies
bac. etiology, GIVE ABX
other bac. signs: sig. pain, prolonged duration (>7-10 d)
acute sinusitis can become a medical emergency if spread to
eye
bone
CNS
xray for sinusitis?
subj. decision, cannot distinguish btw viral, allergic, bac.
* is a MUST if complications suspected
dx tenderness over CN V…
CN V2 for maxillary sinusitis, CN V1 for others
acute sinusitis is tx w/
abx: amoxicillin, amoxicillin-clavulanic acid (Augmentin)
*BUT should be w.held for 10-14 d unless sev. symps : use analgesics, decongestants and “watchfully wait”
DO NOT use antihistamines unless allergic rhinitis
Hypertonic saline nasal irrigation (HSNI)
most common causes of OE
Pseudomonas*, staphylococci (coag +/-) fungi
OE: pus? TM involved? fever?
possibly to all,
if TM, no fluid should be behind, if there is
–>OE + AOM
OE: syst. abx?
NO, local topical abx +/- cortisone
AOM agents: ALL BACTERIA
*Streptococcus pneumoniae (G+ lancet diplococci)
*NTHi (G- coccobacilli)
*Moraxella catarrhalis (G- diplococci)
GABHS (S. pyogenes) and S. aureus (coag+)
Mycoplasma pneumoniae and Chlamydia pneumoniae
*no viral cause, but virus may be present
AOM: pus?
YES; bac inf; it is pyogenic
OME: pus?
NO; serous fluid, biofilm (chron. bac inf)
AOM ddx
fever bulging, opaque, immobile TM otorrhea (discharge) if perf. TM worse complications: can lead to OME hearing impairment, TM rupture, Mastoiditis
OME ddx
NO FEVER
TM MAY BE NORMAL
serous fluid in middle ear (air bubbles, fluid)
otorrhea (serous fluid) if perf. TM
AOM: abx?
complicated: 80% resolve spont., otherwise amoxicillin, augmentin if failure
- need other meds for pain relief
OME: abx?
not unless chronic (>4 mos)
will not help serous effusion
AOM: prevention?
yes:
1. Prevenar 7-valent and 13-valent conjugated vaccine
- prev. inv. pneumococcal disease, pneumo, mening, bacteremia
2. Influenza trivalent inact. vaccine (TIV), LAIV (live atttnd intranasal vaccine)
3. S. pneumo 23 valent polysacc. vaccine: Pneumovax/Pneu-imune
acute myringitis ddx
same bac agents as AOM +/- viral agents
TM inflammation may occur ALONE or w/ OE or OME
bullous: blisters or hemorrhagic
rhinovirus and coronavirus can cause “pharyngitis” but do not
replicate in pharyngeal tissue
these viruses can replicate in pharyngitis
Adenovirus and Strep pyogenes
the primary agent of pharyngitis (URI) and 3rd most common cause of LRI in children
Adenovirus
(non-env.) A–>F (Ad7 *)
most commonly affect kids
main causes of LRIs
- RSV 2.PIV 3. Adenovirus* 4.hMPV
* most severe and highest mortality rate (esp. pneumonia)
adenovirus: causes fever?
yes, also cause of pharyngoconjunctival fever (PCF): summer, swimming pools
adenovirus s/s indistinguishable from
Strep pyogenes infection (GAS)
both: fever, tonsillar exudates, ANT. cerv. lymphadena
pharyngitis is more likely to be viral if
temp is lower, coryza and cough are present, no N/V/abd pn
tx: DO NOTHING; self-limiting (3-7 days)
adenovirus can cause LRT disease that looks like
Pertussis
if adenovirus, will observe these on microscopic observation
mononuclear infiltrates (lymphocytes and monocytic cells)
Streptococcus pyogenes
G+ cocci in chains aerotolerant anaerobe Catalase neg B-hemolytic (GAS or GABHS)
S. pneumoniae
a-hemolytic; causes pneumo, mening, OM, sinusitis, septicemia, conjunc.
S. agalactiae
B-hemolytic: causes neonatal septicemia w. pneumo and mening
S. mutans, S. mitis
a-hemolytic Strep; NF of mouth and l. int, causes dental caries, infective endocarditis
GABHS causes suppurative (pus-producing) disease
pharyngitis, OM, sinusitis, mastoiditis, pneumo
-impetigo, ecthyma, erysipelas, cellulitis, necrotizing fasciitis
GABHS causes non-suppurative, immunpath-med disease
RF, PSRA, PANDAS, AGN
GABHS causes exotoxin-mediated disease (superAgs)
scarlet fever, STSS
the most common cause of BACTERIAL pharyngitis
S. pyogenes (GABHS) **still less common than viral pharyngitis (Ad)
pharyngitis from GAS: self-limiting? tx??
it IS self-limiting, BUT YOU NEED TO TX: want to prevent spread, reduce duration (NOT throat pain), and **prevent agains RH or AGN by suppressing host’s self-limiting imm resp. against GAS (can lead to RH or AGN)
tx: PNC V or cephalosporins
for hypersn. pts: eryth, linco, clindamycin
*also want to treat bac/fungal inf. bc they may not be self-limiting
non-suppurative sequelae of GAS
RF: heart (carditis), skin (nodules), joints (arthritis), CNS (chorea), FEVER
AGN: follow phary. or integumental inf., TIII hypersn., self-limiting
RF tx
bed rest, benzathine penicillin G or procaine penicillin
sympto: salicylates (ASA)
PANDAS
ADHD, Tourett’s, OCD, tic disorder
Scarlet fever caused by
GAS w/ SPEs (strep pyrogenic exotoxins)
complication of pharyng. and integumental inf.
exanthem: scarlatiniform “sand-paper” rash
enanthem: petechia on palate, bleeding, red strawberry tongue
tx to prevent RF/AGN
Lemierre syndrome
thrombophlebitis of IJV-->septic emboli-->lung, brain, joints Fusobacterium necrophorum (G- bacillus, ob. anaerobe)
Corynebacterium diphtheriae
G+ rods, may be club shaped (diphtheroids)
aerobic
*non-invasive
this is req. for diphtheria (“throat distemper”)
exotoxin production: reg by [Fe]: opposite reg
inhibits protein synthesis–>cell death via necrosis–>inflammatory reaction–>fibrinous exudate–>pseudomembrane forms, edema (“bull neck”)–>non-invasive but toxemia (the toxin, not bacteremia) can occur
fever in diphtheria?
yes, low grade
diphtheria: pseudomembrane
gray-black, not pathognomonic (cerv. adenines, GAS)
how to dx diphtheria
clinical findings, Gs (“chinese char.” G+rods), Cx, Elek test to demonstrate toxigenic
diphteria tx
maintain airways, antitoxin abs, abx (PCN G, eryth) as adjunct
Haemophilus influenza
most common cause of acute epiglottitis-AE (Hib)
2nd to S. pneumo for OM, sinusitis (NTHi)
H. flu type aegyptius assoc. w/
conjunct, Brazilian purpuric fever
H. influenza character
v. small G-coccobacilli, ox + (pleomorph in CSF)
anti-phago capsule, type b is most important: strain (PRP) : Hib
grows on chocolate agar
Hib is a frank pathogen, in contrast to..
NTHi: NF of nasopharynx
non-invasive NTHi diseases
OM, sinusitis, conjunc/conjunc-OM synd, bronchitis and pneumo
invasive Hib diseases
mening, bacterimia, facial cellulitis, septic arthritis, secondary bacterial pneumo
AE: fever?
YES
+“air hunger” +insp. stridor + “barking/hot potato voice” + “bull neck”+ “thumb sign” + SUPRAglottic edema + beefy red epiglottis w. purulence
AE org dx
FIRST MAINTAIN AIRWAY med emergency
-Hib, then pneumococcus, then GAS
AE tx
after airway maintained
cefuoxime, cefotaxime, ceftriaxone, TMP-SMX
Hib vaccine…
so now use..
are type II-T-independent so: IgM only, no memory (short term imm.), not protective in kidsswitch to sIgA2, induce memory (B cells), rec. @ 2mos
*don’t bundle w/dTap
other causes of sinusitis: fungal
aka Rhinocerebral mucormycosis