B3.054 - Ear Infections Zuckert Flashcards
what is otalgia
ear pain
what is diagnostic for primary otalgia
abnormal ear exam, discharge, tinnitus, hearing loss, vertigo
why does the inner ear structure not have pain and what are inner ear structures
cochlea, semicircular canals cranial enervation VIII has no pain fibers
secondary otalgia diagnostics
normal ear exam, reffered pain due to sensation fivers from V,VII, XI and X and cervical nerves C2, C3
common causes of otalgia in otitis media
recent URTI, red cloudy and immobile tympanic membrane
common causes of otalgia in otitis externa
swimmers ear ear phone use white discharge
what are causes of secondary otalgia
dental carries, periodontal abcesses, pharyngitis, tonsilitis
epidemiology and signs of malignant (necrotizing) otitis externa
diabetes, elderly immunocompromised painful granulation tissue
what are symptoms ramsay hunt syndrome
from herpes zoster oticus, vesicular rash, vertigo, hearing loss, tinnitus
whats the difference between viral myringitis and OME
similar but no tympanic bulging
what are risk factors for tumors causing otalgia
>50 tobacco alcohol use
what is ramsay hunt syndrome
reactivated VZV spreading to facial nerves paralysis and rash affecting mouth and ears tinnitus hearing loss
H. influenzae can cause
AOM
pseudomonas aeruginosa can cause
AOE
how does H. influenzae gram stain and where is it on the tree
gram - negative mcconkey oxygen positive
describe the physical characteristics of H. influenzae
small gram - rods/coccobacilli
what are the complex nutritional requirements of Haemophilus sp
X factor - hematin V factor - NAD
how many capsular antigenic serotypes does H. influenzae have
6 (a-f)
whats the most virulent type of H. inluenzae
Hib
what are non typable strains of Haemophilus inlfuenzae
non encapsulated rarely cause invasive disease
what does H. ducreyi cause
STD soft chancre/chancroid (panful)
what does H aegyptius cause
conjuctivitis
Hib colonizes what using what
oropharynx using adhesins like fimbriae, IgA protease
what causes local inflammation in Hib
LPS Impairment of ciliary function damage to respiratory epithelium
invasion of blood stream and bacteremia is cause by what in Hib
PRP (polyribitol capsule)
what type of antibody is protective for Hib
anti PRP
what aids Hib in hematogenous spread
PRP
what causes disseminated disease in Hib
LPS
what are the only hosts of Hib
humans
how is Hib transmitted
respiratory droplets, mainly pediatric disease
what does the Hib vaccine have in it
purified PRP conjugated to carrier proteins
what is the combination vaccine for Hib called and what is it a combination of
DTap-Hib and Hepatitis B-Hib DTap has Diphtheria toxoid, mutant diphtheria toxin, tetanus toxoid, meningococcal membrane protein
how does the vaccine help your immune system
Creates T cell dependent antigens, protective antibody response is created in >2mo
what is the immunization schedule of Hib
2, 4, 6 and 12-15 moths
who is the Hib vaccine not recommended for
>5 yo unless pt has sickle cell, asplenia, immunodeficiency, HIV
how does Hib gram stain and what specimen do you get
CSF or synovial fluid Gram -
what test can you do for the capsule of Hib
latex agglutination
what does a culture media for Hib require
Factor V and X
what other organism do you plate with in a culture of Hib
Staph aureus because it has hemolysin RBCs releasing factor V and X allowing
NTHi is not serum resistant, what does that mean
it lacks a capsule so its infection is localized and not able to spread to blood
what are common issues caused by NTHi
otitis media sinusitits pneumonia
how do you treat invasive H influenzae
3rd gen cephalosporins ceftriaxone
how do you treat otitis media, sinusitis caused by H influenzae
ampicillin cephalosporin fluoroquinolone (ciprofloxacin)
major sequelae of an Hib infection
meningitis
describe the gram identification of psuedomonas and where if falls on tree
Gram - grows on mcconkey + Lactose - Glucose -
is pseudomona motile
yes
where do you find pseudomonas
ubiquitous in environment, soil, water, plants, animals, humans,
how do people typically get infected with psudomonas
its a common nosocomial pathogen from hospital stays
infections of psudomonas are found where on the body
skin pulmonary outer ear eye
what is alginate
P. aeruginosa capsule
what does the p. aeruginosa capsule do
prevents phagocytosis and contributes to antibiotic resistance adhesin
describe the structure of the capsule
polymer of mannuronic and glucuronic acid
how is p. aeruginosa production highly regulated
environmental and quorum sensing produced at high levels in lungs
what does a culture of p aeruginosa look like
mucoid colonies, shiny, alginate +
what does p aeroginosa look like in vitro
production ceases, smooth and pigmented, pycyanin, green colonies, flagella +, pilli +
what is this and differentiate between left and right
left is acute and right is chronic (has capsule)
p. aeruginosa
exotoxins of p aeruginosa
Exotoxin A, S, U
what does exotoxin A do
A-B toxin: A subunit ADP ribosylates elongation factor EF-2 affecting protein synthesis
what does exotoxin S do
major virulence factor
injected T3SS effector protein
disrupts signal transduction and blocks phagocytosis
what does exotoxin U do
cytotoxic for macrophages
what does p aeruginosa do to elastase and whats it regulated by
degrades elastin (protein in pulmonary and endothelial tissue)
Production regulated by quorum sensing
what is quorum sensing
osmolarity/nitrogen sensing of external environment
what type of infection do otherwise healthy individuals
folliculitis, hot tub rash
otitis externa (swimmers ear)
Eye infections associated with trauma
default treatment for P.a. otitis externa
eardrops
treatment for p.a. otitis externa mild
acetic acid + propylene glycol + hydrocortisone
moderate to severe treatment for P.a. otitis externa
ciprofloxacin + hydrocortisone
what do you not give for P.a. otitis externa if tympanic membrane is ruptured
neomycin
what is used for prevention of p.a. otitis externa
alcohol ear drops
P.a. diseases in immunocompromised
bacteremia
burn would infections
malignant otitis externa
pulmonary infections
when after a burn wound would you see pseudomonas infections
>2 weeks
whats the DOC for psudamonas caused malignat otitis externa
IV ciprofloxacin
who do you see P.a. infections in
pts with COPD, CF, neutropenia
by what age and how many CF pts have P.a. colonization
80-90%, by age 3
P.a. biofilm formations are resistant to what
phagocytosis, complement, antibodies
symptoms of pseudomonas pneumonia
fever, chills, sever dyspnea, cyanosis, productive cough
risk factors of P.a. pneumonia
neutropenia, chronic lung disease, CHF, use of mechanical ventilators, lung burns
what types of patients are more likely to get P.a. pneumonia
ICU pts and nursing home residents
describe the ways to identify P.a. in lab
obligate aerobe
catalase +
oxidase +
green pigmented, often fluorescent colonies
what causes green pigmented P.a.
pyocyanin - blue, antibiotic pigment
Fluorescein
what does pyocyanin do
cytotoxic to eukaryotic cells, oxidative stress
what are siderophores
pyoverdin and pyochelin
what is distinct about the smell of p.a.
fruity (grapes, tortillas)
where is PYO found
airway secretions
what does PYO cause
low ATP (cilia, CFTR)
Low NADPH
neutrophils
initial empiric combo treatment for P.a.
antipseudomonal beta lactam + beta lactamase inhibitor +aminoglycoside
what is colistin and what does it do
polymixin E
last resort, solubilizes bacterial membranes
