URTIs Flashcards
What is pharyngitis?
Acute inflammation of the nasopharynx or oropharynx
Clinical presentation of pharyngitis? (5)
Acute onset of sore throat Pain on swallowing Erythema, with inflammation of the pharynx or tonsils (with or without patchy exudate) Fever Tender and swollen lymph nodes
Viral microbiology of pharyngitis
rhinovirus, coronavirus, influenza, parainfluenza, Ebstein-Barr
Bacterial microbiology of pharyngitis
Group A beta-hemolytic Streptococcus pyogenes
Which age group has 1 point in the Modified Centor Criteria?
3-14 years
children higher prevalence
Which complication of Steptococcus pyogenes pharyngitis is prevented by early initiation of effective antibiotics?
Acute rheumatic fever
When do complications arise for bacterial pharyngitis? What are they?
1-3 weeks later
Acute rheumatic fever (prevented by early initation of effective antibiotics)
Acute glomerulonephritis (not prevented by early initiation of antibiotics)
How is bacterial pharyngitis diagnosed?
Using the Modified Centor Criteria
5 criteria: Age, Absence of cough, fever, swollen lymph nodes, tonsillar exudate
4-5 points: high risk, treat empirically
First line antibiotics for pharyngitis? What are the alternatives? Treat for how long?
First line: Penicillin VK
Alternatives: Amoxicillin, cephalexin, clindamycin, clarithromycin
Treat for 10 days
Why is augmentin not recommended for bacterial pharyngitis?
Augmentin covers aneaerobic and gram negaitve coverage, which is not needed. Amoxicillin is good enough (Use narrowest spectrum possible)
What is rhinosinusitis
Acute inflammation of the paranasal or nasal mucosa
How is sinusitis diagnosed?
> = 2 major symptoms; OR 1 major + >=2 minor symptoms
Major symptoms (7): Purulent anterior nasal discharge Purulent or discolored posterior nasal discharge Nasal congestion/obstruction Facial congestion/fullness Facial pressure/pain Hyposmia/anosmia Fever
Minor symptoms (6): Halitosis, headache, ear pain/pressure/fullness, dental pain, cough, fatigue
Microbiology of sinusitis
Viral > bacterial
Viral: adenovirus, rhinovirus, parainfluenza, influenza
Bacterial: H. influenzae and S. pneumoniae most common, Moraxella catarrhalis and S.pyogenes also possible
Bacterial sinusitis commonly arise from viral URTIs. True or false?
True
Inflammation results in sinus obstruction; nasal mucosal secretions are trapped, becomes a medium of bacterial trapping and multiplication
How is bacterial sinusitis diagnosed?
Presence of sinusitis + presence of any ONE criterion:
- Persistent of symptoms > 10 days AND not improving (viral sinusitis resolves in 7-10 days)
- Severe symptoms at onset (purulent nasal discharge x 3-4 days or high fever >= 39 degC)
- “Double sickening” (worsening symptoms after 5-6 days after initial improvement - most likely bacterial sinusitis after viral URTI)
Treatment for bacterial sinusitis
1st line antibiotic: amoxicillin or amoxicillin-clavulanate
Alternatives:
- Respiratory FQs: levofloxacin, moxifloxacin
- Trimethoprim/sulfamethoxazole
-Cefuroxime
Adults: treat for 5-10 days
Children: treat for 10-14 days
Which antibiotics are NOT suitable for local setting for treatment of bacterial sinusitis?
Clarithromycin, azithromycin, doxycycline
Which fluoroquinolone is not a respiratory fluoroquinolone? What does it lack activity against?
Ciprofloxacin, as it has poor activity against Streptococcus pneumoniae
Treatment considerations for S pneumoniae
Mutation of Penicillin binding protein which increases the MIC of penicillins
Prefer to use amoxicillin over penicillins due to more favourable PK
Prefer high dose amoxicillin for effective treatment
Treatment considerations for H influenzae
Beta-lactamase production Inhibited by beta-lactamase inhibitor Use augmentin over amoxicillin only if: - recent hospitalisation - recent antibiotics use - failure to improve after 72 hours of antibiotics
What is acute otitis media?
Infection of the middle ear space resulting in inflammation and fluid accumulation
Clinical presentation of AOM
Ear pain, ear fullness, ear popping, ear discharge, fever, hearing impairment, dizziness, non-specific in young infants (excessive crying, changes in sleep or behavioral pattern, ear rubbing)
Risk factors for AOM
Age <5 years old, attending day care, siblings, supine position during feeding, exposure to tobacco smoke at home, pacifier use, winter season
Prevention of AOM
avoid exposure to tobacco smoke
exclusive breastfeeding for 1st 6 months
minimise pacifier use
vaccinations - influenza, pneumococcal, h influenzae type B vaccine
Microbiology of AOM
Virus = Bacterial
Virus: adenovirus, rhinovirus, respiratory syncytial virus, parainfluenza virus
Bacteria: S pneumoniae, H influenzae, Moraxella catarrhalis
Approaches to antibiotics for AOM
Immediate initiation vs observation period
When can observation period be considered for patient with AOM?
- > =6 months
- No otorrhea
- Lack of severe illness (no fever >=39 deg in the last 48 hours, otalgia >= 48 hours, moderate to severe otalgia)
- Possible for close follow up
- Shared decision making with the parent/caregiver
Which are candidates for observation period?
6 months to 2 years: unilateral AOM with no otorrhea
>= 2 years: bilateral AOM with no otorrhea, unilateral AOM with no otorrhea
Under what circumstances would amoxicillin-clavulanate be preferred over amoxicillin in the treatment of AOM?
amoxicillin in the last 30 days
history of purulent conjunctivitis
history of AOM non-responsive to amoxicillin
Treatment options for AOM
1st line: amoxicillin or augmentin
use augmentin if recent amoxicillin use, history of purulent conjunctivitis, history of AOM non-responsive to amoxicillin
alternatives: cefuroxime, ceftriaxone (IM), clindamycin (for severe penicillin allergy, no coverage for h influenzae)
What are severe symptoms of AOM?
Moderate-to-severe otalgia
otalgia >=48 hours
fever >= 39 degC in the last 48 hours
Compared to common cold, what symptoms are more usual in influenza?
Chills, body aches, fever, fatigue, body weakness, chest discomfort, cough, headache, acute onset
Symptoms more like COVID-19 and more unlike influenza
Nausea, vomiting, diarrhea, loss of taste or smell
Microbiology of influenza
3 strains - influenza A, B and C
Complications of influenza
Viral pneumonia
post-influenza bacterial pneumonia (esp S. aureus)
respiratory failure
exacerbate underlying pulmonary or cardiac comorbidities
febrile seizures
myocarditis or pericarditis
Who are those at “high-risk” for influenza related complications?
Children <5 years
Elderly >65 years
Women who are pregnant or within 2 weeks post partum
Residents of nursing homes or long-term care facilities
Obese individuals with BMI >40kg/m2
Individuals with chronic medical conditions
What are some prevention strategies for influenza?
Good personal hygiene, health lifestyle, vaccination
How is influenza diagnosed?
molecular tests like reverse-transcriptase polymerase chain reaction (RT-PCR) - only for inpatients, most outpatients are treated empirically
For which patients do you need to initiate treatment as soon as possible for suspected or documented influenza?
Hospitalised
High risk for complications
Severe, complicated or progressive illness
may be considered for outpatients presenting within 48 hours of symptom onset
What is the antiviral used for influenza? What is the mechanism of action?
Oseltamivir, a neuraminidase inhibitor which interferes with protein cleavage, inhibiting the release of new virus
Which strains of influenza is oseltamivir active against
Influenza A and B
Does oseltamivir need renal dose adjustment? What is the usual dosing?
Yes.
Usual adult dosing is 75mg PO BD for 5 days
