IC15 PR3151 URTI Flashcards
what is the pathophysiology of URTI
transmission via
- droplets or aerosols spread through the air when person is talking/sneezing/coughing etc.
- indirect contact (e.g., surfaces)
- sharing food
inhalation and invasion into the upper mucosa
what are the GENERAL risk factors for URTI?
1) anatomical abnormalities e.g., facial dysmorphic changes, nasal polyposis
2) poor hand/personal hygiene
3) exposure to children e.g., schools and daycare
4) immunocompromised (e.g., CSC use)
5) chronic respiratory diseases e.g., asthma, allergic rhinitis
6) smoking
host defence to URTI?
1) mucocilliary action from lower respiratory tract.
2) mucus.
3) angle between nose and pharynx to prevent particles from falling into the tract.
4) nostril hair
5) adenoids and tonsils that have immunological cells.
what methods for prevention of URTI?
1) adequate hygiene; mitigating risk factors, e.g., controlling chronic respiratory diseases
2) vaccinations: pneumococcal, haemophillus infl-, influenza
when to initiate for ABX in URTI?
NEVER for common cold and influenza.
MAYBE: pharyngitis, rhino sinusitis, otitis media
what is the clinical presentation of common cold
what other exclusions?
physical exam
low grade fever, rhinorrhea, nasal blockage, productive cough, sore throat, sneezing, some headache/body ache
usually no high fever and bilateral auscultation of lungs (clear) + normal heart rate
what are the pathogens causing common cold
usually rhinovirus and coronavirus.
selection of abx regimen for common cold?
DO NOT USE ABX for common cold
how to monitor response for common cold
usually self limiting and will resolve in 7-10 days
if no resolution after 10 days, to go see a doctor.
usually cough may be 2-3 weeks due to post nasal drip
counsel patient that will usually feel better after 3-4 days and that it is normal for the nasal discharge to change colour.
common cold step 2: do we need to identify for pathogens?
no steps needed. typically no need to test for pathogens unless to differentiate from coronavirus or influenza.
what is the presentation of influenza
fever, malaise, anorexia, myalgia, chills, headache
nasal discharge, dry cough, sore throat.
some elderly may present with mental confusion.
what are the risk factors for influenza complications
elderly >65
children <5
pregnant and ≤2 weeks post-partum
long term care or nursing homes
obese individuals with BMI >40
individuals with chronic medical conditions
when do you test for influenza pathogens?
hospitalised patients or long term care patients.
what are the tests used for influenza pathogen testing?
rapid diagnostic testing, POCT- immunofluoroscence, enzyme immunoassay, immunochromatographic test,
reverse transcriptase PCR
what kind of complications can result from influenza
primary viral pneumonia and secondary bacterial pneumonia (often from s.aureus, strep pneumonia, haem influenza), exacerbation of chronic respiratory disease, and myocarditis.
when to initiate treatment for influenza
patients who are hospitalised, have high risk for complications, and have severe, complicated, progressive disease.
BEST to start treatment within 48 hours on onset, but may be up to 5 days if patient is severely ill.
what is the drug regimen for influenza?
counselling points (include ADR)
oseltamivir PO 75mg BD x 5 days
may cause GI side effects (N/V) and headaches.
renal dose adjustment if CrCL <60ml/min
what is the MOA for oseltamivir
neuramidase inhibitor that prevents protein cleavage and release of new virus.
what are the pathogens for influenza?
influenza A
- subtypes based on the surface proteins: neuramidase (N) and hemagluttinin (H)
influenza B
- two lineages: yamagata and Victoria
influenza C
- causes mild febrile URTI.
what is the epidemiology of influenza?
influenza A and B are seasonal epidemic.
influenza A is capable of being a pandemic.
influenza C is not epidemic.
how to monitor (step 4) for influenza?
if not resolved after 10 days/worsening dyspnoea or cough/improvement of symptoms that then cause fever (may suggest secondary bacteria infection?)
= revisit doctor
usually symptomatic for 1 week
influnenza vaccine regimen and counselling?
take once a year
IM administration
recommended for ≥6 months esp those with high risk complications
takes about 2 weeks to confer immunity
75% efficacy
influenza vaccine types?
seasonal:
northern hemisphere season: nov to feb
southern hemisphere season; may to jul
what are the general symptoms for pharyngitis?
1) fever
2) inflamed or erythematous tonsils or pharynx w/w/o patchy exudates (pus)
3) swollen or tender lymph nodes
4) sore throat
what are the symptoms of viral pharyngitis?
2(FC) RHOM
fever (low grade)
fatigue
cough
conjunctivitis
rhinorrhea
hoarse voice
oropharyngeal lesions e.g., ulcers
malaise
what are the symptoms of bacterial pharyngitis?
fever
cervical lymphadenopathy
patchy tonsillar exudates
what are the complications of viral pharyngitis?
disease progression
generally self-limiting
what are the complications of bacterial pharyngitis?
disease progression
self limiting or complications which occur from 1-5 weeks after (usually 2-3 wks)
1) acute rheumatic fever (prevented with early initiation of abx)
2) acute glomerulonephritis (cannot be prevented with abx)
what are the likely pathogens for pharyngitis? (bact vs viral)
viral > bacterial
viral is 80%, bacterial 20%
viral: rhinovirus, coronavirus, epstein-barr, influenza, parainfluenza
bact: grp A beta hemolytic strep –> usually S.pyrogenes
what to use to test for bacterial pharyngitis?
MODIFIED CENTOR CRITERIA
what are the contents of the modified centor criteria
1) fever > 38
2) tonsillar exudates
3) absence of cough
4) tender or swollen lymph nodes
5) age:
- 3-14 = 1 pt
- 15 - 44 = 0 pt
- >44 = -1 pt
what is the grading scale for modified Centor criteria
0 or 1 point
- no risk
2 or 3 point
- risk + test and initiate abx if positive
4 or 5 points
- high risk
- test
- start empiric treatment
what are the testing methods for pharyngitis and how long for results to show
RADT (minutes)
gold standard: throat culture (24-48hours)
pharyngitis goals of treatment
1) reducing acute symptoms
2) preventing delayed/acute complications
3) preventing transmissions (no longer infectious after 24hours of abx)
what is the (first line) empiric treatment for bacterial (s pyrogenes) pharyngitis
1) PO penicillin 250mg Q6
2) PO amoxicillin 500mg Q12
x10 days (5 days for azithromycin)
what is the (pen allergy) empiric treatment for bacterial (s pyrogenes) pharyngitis
IF ALLERGIC to penicillins
3) PO cephalexin 500mg Q12
4) Azithromycin 500mg OD
5) Clarithromycin 250mg Q12
6) Clindamycin 300mg Q8
x10 days (5 days for azithromycin)
what is the pathogenesis of acute rhinosinusitis (sinusitis)
Pathogenesis
Direct contact with droplets of infected saliva or nasal
secretions
Bacterial cases usually preceded by viral URTIs (e.g. common cold, pharyngitis)
Inflammation results in sinus obstruction
Nasal mucosal secretions are trapped
Medium of bacterial trapping and multiplication
what are the common symptoms of sinusitis
Purulent nasal discharge
Facial pain or pressure
Fever
Nasal congestion and obstruction
Reduced sense of taste or smell (hyposmia or anosmia)
Headache
Cough
Ear fullness or pressure
Bad breath
Dental pain
when should patients be referred to the ED for sinusitis
evidence of spread of infection to the orbits or the central nervous system should be referred to the emergency department for further evaluation including imaging.
Symptoms suggestive of orbital cellulitis or central nervous system infection include–
- Limited ocular movements
- Acute vision changes
- Confusion
- Unilateral weakness
what are the most common pathogens for sinusitis
most common:
strep pneumoniae
haemophilus pneumo
others
strep pyrogene
moraxella
anaerobic bacteria
when to treat bacterial sinusitis with antibiotics ?
if one or more of the following
1) no clinical improvement of symptoms after 10 days
2) severe symtoms: purulent discharge, fever more than 39deg, facial pain more than 3 consecutive days
3) worsening of symptoms after initial improvement for more than 3 days (new onset fever, headache, increased nasal discharge)
what is the (first line) empiric treatment for bacterial (s pyrogenes) sinusitis
PO AMOX 500MG Q8
PO AMOXICLAV 625 Q8
x5-7 days
what is the (pen allergy) empiric treatment for bacterial (s pyrogenes) sinusitis
PO CEFUROXIME 500MG Q12
PO CIPRO 500MG OD
PO MOXI 400MG OD
x5-7 days
how to monitor for response for sinusitis (step 4)
resolution should be 7-10 days (with or without antibiotics)
see doctor if worsening or persisting symptoms
antibiotics adr
what antibiotics to avoid for sinusitis and why?
tetracyclines, bactrim, macrolides
to avoid due to increasing resistance to strep pneumonia
what antibiotics to avoid (slowly or generally) for pharyngitis and why>
macrolides
due to increasing resistance
