URTI - Pharyngitis, Sinusitis, AOM & Influenza

Question 1

What is pharyngitis?

Answer 1

Acute inflammation of oropharynx/ nasopharynx

Question 2

Clinical presentation of Pharyngitis

Answer 2

• Acute onset of sore throat
• Pain when swallowing
• Erythema & inflmm of pharynx & tonsils (May have patchy exudates)
• Tender & swollen lymph nodes
• Fever

Question 3

Microbiology of Pharyngitis

Answer 3

1) Viruses (80%)
- rhinovirus, coronavirus, influenza, parainfluenza, epstein-barr

2) Bacteria
- Strep pyrogens (Group A Beta-hemolytic Streptococcus)
- #1 cause

Question 4

Pathogenesis of Pharyngitis

Answer 4

Direct contact with droplets of infected saliva/ nasal secretions (Short incubation: 24-48hrs)

Question 5

Complications of Pharyngitis

Answer 5

S. pyrogens Pharyngitis (Self-limiting/ Complications)

• 1-3 weeks later
  i) Acute rheumatic fever
• Can cause damage to joints, heart tissue fever
• Prevented with early initiation of effective antibiotics

ii) Acute glomerulonephritis
- Kidney damage
- NOT preventable by antibiotics

(Viral: Self-limiting)

Question 6

Challenges in managing Pharyngitis

Answer 6

Viral & bacterial have similar clinical presentations!

Antibiotics use in Bacterial Pharyngitis:

1) Prevent Acute rheumatic fever
2) Shorten duration of symptoms by 1-2days
3) Reduce transmission (no longer infectious after 24hrs of antibiotics)

Question 7

Diagnosis of Pharyngitis

Answer 7

1) Clinical diagnosis with criteria (higher score, > likely)
- Criteria: Fever > 38C, Swollen tender anterior cervical lymph nodes, tonsillar exudate, no cough, 3-14yo
0-1 points: Viral; self-limiting
2-3 points: Optional, but usually will just start
4-5 points: Start antibiotics

2) Throat culture (24-48hrs)
- gold standard but not practical

3) Rapid antigen detection test (mins)
- expensive, not usually done

Question 8

Treatment of Pharyngitis

Answer 8

1) Penicillin VK (1st line): 250mg PO QDS/ 500mg BD
[P: 250MG PO BD-TDS]
2) Amoxicillin: 1g PO OD/ 500mg PO BD
[P: 50mg/kg/day* or divided BD*]
3) Cephalexin
4) Clindamycin: 300mg PO TDS
[P: 7mg/kg TDS]
5) Clarithromycin

Duration: 10 days
(though clinical response expected within 24-48hrs)

Question 9

What is rhinosinusitis (sinusitis)?

Answer 9

Acute (within 4 weeks) inflammation & infection of the paranasal & nasal mucosa

Question 10

Clinical presentation of Sinusitis

Answer 10

> = 2 major/ 1 major + 2 (or more) minor symptoms

Major:

• Purulent anterior nasal discharge
• Purulent/ discoloured posterior nasal discharge
• Nasal congestion/ obstruction
• facial congestion/fullness
• facial pain/ pressure
• hyposmia (decreased sense of smell) / anosmia
• fever

Minor:
- HA, ear pain/pressure/fullness, halitosis (bad breath), dental pain, cough, fatigue

Question 11

Microbiology of Sinusitis

Answer 11

1) Virus (>90%)
- rhinovirus, adenovirus, influenza, parainfluenza

2) Bacteria (<10%)
- Streptococcus pneumoniae & Haemophilus influenzae (most common)
- Moraxella catarrhalis
- Streptococcus pyrogens

Question 12

Pathogenesis of Sinusitis

Answer 12

Direct contact with droplets of infected saliva/ nasal secretions, usually preceded by viral URTIs

• > Inflammation results in sinus obstruction
• > Nasal mucosal secretions are trapped
• > Medium of bacterial trapping & multiplication

Question 13

Diagnostic challenges of Sinusitis

Answer 13

Bacterial & Viral have similar symptoms!!!

Limited use of diagnostic tests:
1) Clinical diagnosis (USE THIS)
Presence of sinusitis + 1 of these criteria:
- Symptoms persist > 10 days & doesn’t improve
(vs Viral Sinusitis: self-limiting)
- Severe symptoms at onset
(Purulent nasal discharge x 3-4 days/ high fever >= 39C)
- “Double sickening”
(Symptoms worsen 5-6days after initial improvement)

2) Imaging tests: non-specific, non-discriminatory

3) Sinus aspirate (gold standard):
invasive, painful, time-consuming

Question 14

Treatment of Sinusitis

Answer 14

1st line:
i) Amoxicillin: 1g PO TDS*
[P: 80-90mg/kg/day* or divided BD]
ii) Augmentin: 625mg PO TDS/ 1g PO BD*
[P: 80-90mg/kg/day* or divided BD*]

Alternatives:

i) Levofloxacin (500mg PO OD*)/ Moxifloxacin
ii) Trimethoprim/ Sulfamethoxazole
iii) Cefuroxime

Duration: Adults (5-10 days), Pediatrics (10-14 days)

Question 15

Why is Amoxicillin preferred over Penicillin for treatment of S. pneumoniae?

Answer 15

Favourable PK, amoxicillin can get higher bioavailability

• S. pneumoniae -> Multi-step PBPs mutation -> Increases penicillin MIC
• “High-dose” Amoxicillin [80-90mg/kg/day (pediatrics); 1g (adults)] for effective treatment

Question 16

Considerations of H. influenzae?

Answer 16

• Beta-lactamase production

- Inhibited by beta-lactamase inhibitor

Question 17

When to use Augmentin > High-dose Amoxicillin for Sinusitis?

Answer 17

1) Recent course of antibiotics (~30days)
2) Recent hospitalization
3) Failure to improve after 72hrs of amoxicillin

Question 18

What is Acute Otitis Media?

Answer 18

Infection of the middle ear space resulting in inflamm & fluid accumulation

Question 19

Clinical presentation of AOM

Answer 19

• Ear pain (eg. otalgia) / discharge (eg. otorrhea) / popping/ fullness, hearing impairment, dizziness, fever
  (Non-specific in young infants)

Question 20

Risk factors for AOM

Answer 20

- Siblings/ Daycare
 (Increase chance for interactions to pick up infection)
- Supine position during feeding
- Exposure to tobacco smoke @ home
- Pacifier use
- Winter season

An infection in pediatric patients (usually < 5yo)
- Eustachian tube is more straight, easier backflow of fluid to ears

Question 21

Prevention of AOM

Answer 21

• Avoid exposure to tobacco smoke
• Exclusive breastfeeding for 1st 6 mths
• Minimise pacifier use
• Vaccinations (Influenza/ Pneumococcal/ H. influenzae type B vaccine)

Question 22

Pathogenesis of AOM

Answer 22

Viral URTIs (ie. common cold) -> Secretions & inflammation -> Eustachian tube obstruction -> -ve Eustachian tube pressure -> Reflux of secretions into middle ear [Medium for bacterial accumulation & growth]

Viral URTIs (ie. common cold) -> Nose sniffing -> Reflux of secretions into middle ear

Question 23

Microbiology of AOM

Answer 23

1) Bacterial (55-60%)
2) Viral (40-45%)
- S. pneumoniae, H.influenzae, Moxarella catarrhalis

Question 24

Diagnosis of AOM

Answer 24

Pneumatic otoscope (standard tool)

Diagnostic criteria:

• Acute onset (<48hrs)
• Otalgia (holding, tugging or rubbing of ear) OR erythema of tympanic membrane
• Bulging of tympanic membrane (Fluid buildup that creates increased pressure)

Question 25

Challenges in management of AOM

Answer 25

Difficult to distinguish between bacterial/ viral!!!

• Prompt antibiotic initiation decreases duration of symptoms by ~1 day
• ~80% of cases resolve in 3-4days without antibiotics
• Overprescribing antibiotics -> Resistance ):

Question 26

Type of approaches towards AOM

Answer 26

1) Immediate initiation

2) Observation period (Supportive care for 48-72 hrs first, assess again afterwards)
- Criteria: >= 6 months of age, non-severe illness (minor otalgia not more than 48hrs, no fever >39C), no ottorhea, possible for close follow-up, shared decision making

Eligibility:

i) 6mths-2yo: Unilateral AOM without otorrhea
ii) 2yo & above: Unilateral/Bilateral AOM without otorrhea

Question 27

Treatment of AOM

Answer 27

1st line: Amoxicillin: 80-90mg/kg/day* or divided BD*
- Needs to: Not have taken amoxicillin in past 30days + No concurrent purulent conjunctivitis + No penicillin allergy

Alternative:
i) Augmentin: 80-90mg/kg/day* or divided BD*

Penicllin-allergy:

ii) Cefuroxime: 30mg/kg/day* or divided BD
iii) IM Ceftriaxone

If really no choice, severe penicillin allergy:

iv) Clindamycin
- Effective against S. pneumoniae only (Gram +)

Question 28

Treatment duration of AOM

Answer 28

Improvement expected in 48-72hrs

Below 2yo: 10 days
2-5yo, non-severe: 7 days
Above 6yo, non-severe: 5-7 days

Severe illness (mod-severe otalgia/ otalgia >= 48hrs, Fever > 39C in the last 48hrs): 10 days

Question 29

Symptoms of Influenza

Answer 29

Fever, body aches, chills, fatigue/weakness, stuffy/runny nose, sore throat, chest discomfort, HA

Question 30

Microbiology of Influenza & its clinical presentation

Answer 30

A: Humans/swine/equine/avian/multiple other species
- More severe illness; significant mortality in young
persons
- Epidemics & pandemics
B: Human only
- Severe illness in older/ higher risk persons
- Less severe epidemics
C: Humans, swine
- Mild respiratory illness w/o seasonality
- No epidemics

Question 31

Complications of Influenza

Answer 31

• Viral pneumonia
• Post-influenza bacterial pneumonia (particularly those caused by S.aureus; Mortality > 30%)
• Resp failure
• Exacerbate pulmonary/ cardiac comorbidities
• Febrile seizures
• Myocarditis/ Pericarditis

Question 32

Groups that are at “high risk” for influenza-related complications

Answer 32

Child < 5yo/ Elderly >= 65yo
Pregnant women/ within 2 weeks post-partum
Residents of nursing homes/ long term facilities
Obese indvs (BMI >= 40)
Indvs with chronic medical conditions (Asthma/ COPD/ HF/ Diabetes/ CKD/ Immunocompromised)

Question 33

How to prevent Influenza?

Answer 33

1) Good personal hygiene
2) Healthy lifestyle
3) Vaccinations
- Inactivated trivalent/ quadrivalent vaccine
- Adm IM 1x/year
- Recommended for all individuals > 6months

Note: Chemoprophylaxis NOT recommended
- To avoid sub-therapeutic dosing which can increase resistance

Question 34

Diagnostic tests for influenza

Answer 34

1) Viral cultures (hard to perform; not recommended)
2) Molecular tests
- Outpatient: Mostly treated empirically based on clinical presentation
- Inpatient: RT-PCR test to identify pts with Influenza

Question 35

Treatment of influenza

Answer 35

For documented/suspected influenza:
Initiate asap within 48hrs of symptom onset (> 48h contradicting info) for indvs with ANY of these:
- Hospitalised
- High risk for complications
- Severe/complicated/progressive illness

Antiviral choice:

1) Oseltamivir (75mg PO BD* x 5d)
- Neuraminidase inhibitor (interfere with protein cleavage, inhibiting virus release)
- Active for Influenza A/b
- ADE: HA, mild GI effects (well tolerated)