JC129 (Family medicine) - Upper Respiratory Tract Infections

Question 1

Causative pathogens of URTI

Answer 1

>90% viral
 Rhinovirus
 Adenovirus
 Influenza
 Parainfluenza
 Respiratory syncytial
 Coronavirus

<10% bacterial
 Group A beta-haemolytic Streptococcus
 Haemophilus influenzae
 Streptococcus pneumoniae
 Branhamella catarrhalis (Moraxella catarrhalis)
 Staphylococcus aureus

Question 2

Types of URTI

Answer 2

o Coryza (the common cold)
o Pharyngitis (viral or bacterial)
o Influenza
o Tonsillitis (viral or bacterial)
o Acute laryngitis (viral or bacterial)
o Others

Question 3

Symptoms of URTI

Answer 3

URT symptoms + features of acute infection

Respiratory:
 Cough/ sputum
 Runny nose/ sneeze
 Nasal congestion
 Sore throat
 Hoarseness

Infection: 
 Chills
 General malaise
 Fever
 Loss of appetite
 Nausea/ vomiting
 (Dyspepsia/ abd pain)

Question 4

Outline history taking questions for URTI

Answer 4

• Cough: productive or non-productive
• Course: acute/ subacute/ chronic/ recurrent
• Emergencies (red flags): cyanosis/ dyspnea/ drooling
• Nasal symptoms: runny nose and nasal congestion
• Sore throat
• Hoarseness of voice
• Systemic illness/ discomfort
• Constitutional symptoms

PMH:

• History of recurrent/ complicated URTI
• History of atopy
• Chronic lung diseases
• Drug use, previous treatment

Social:

• Family history of atopy
• Recent URTI in close contacts
• Smoking habit

Question 5

Ddx productive cough

Answer 5

URTI
Emergencies (red flags): cyanosis/ dyspnea (e.g. malignant pleural effusion)/ drooling
Serious: pneumonia, TB, cancer, CHF
Pitfalls: allergic rhinitis, asthma, COPD, bronchiectasis, drugs (ACEI), GERD

Question 6

Ddx nasal congestion and runny nose

Answer 6

URTI
Serious: NPC
Pitfalls: allergic rhinitis, polyps, foreign body in nose, & sinusitis

Question 7

Complications of viral URTI

Answer 7

snoring, loss of smell (anosmia), otitis media, sinusitis

Question 8

Ddx sore throat

Answer 8

Emergency: drooling of saliva - Acute epiglottitis

Serious: peritonsillar abscess (quinsy), TB, lymphoma, bacterial tonsillitis

Pitfalls:
 Postnasal drip, food irritation, foreign body, infectious mononucleosis (EBV)
 Enlarged tonsils are normal in children

Question 9

Ddx hoarseness of voice

Answer 9

Chronic: vocal cord polyps/nodules

Serious: carcinoma of larynx, Acute epiglottitis, croup

Pitfalls: sputum, laryngeal injury/compression, trauma from intubation

Question 10

Describe the cough and sputum production due to URTIs

Answer 10

Symptoms:
 Irritating cough (postnasal drip)/ sore throat
 Scanty sputum, white/yellow
 General condition good (no SOB/ chest sign)

Course:
 Acute (daytime, before/ after sleeping)
 Self-limiting (1-3 weeks)

Question 11

Describe the nasal symptoms due to URTI

Answer 11

 Acute onset
 Copious clear watery discharge
 Sneezing++, relatively little itchiness
 Little diurnal variation
 Self-limiting (3-5 days)

use nasal speculum to look at anterior compartment of nose: allergic rhinitis if nasal mucosa is congested and swollen

Question 12

Describe different presentations of sore throat in URTIs

Answer 12

Viral: acute onset of sore throat (Exudates can mean viral/ bacterial)

Acute epiglottitis - sore throat with SoB and drooling saliva

Bacterial tonsillitis - sore throat with trismus

Question 13

Criteria for strep. throat infection

Answer 13

CENTOR Criteria for sore throat:
- estimates probability that the pharyngitis is streptococcal, and suggests its management course

Four criteria* (1 point for each positive criterion):

1. History of fever
2. Tonsillar exudates
3. Tender anterior cervical adenopathy
4. Absence of cough

Modified Centor Criteria (add the patient’s age to the criteria):
Age <15 add 1 point
Age >44 subtract 1 point

Scores range: -1 to 5
-1 to 1 (low risk of strep throat) = No antibiotic or throat culture necessary
2-5 (high risk) = Consider rapid strep testing and/or culture, treat with an antibiotic if result is positive

Question 14

Typical duration of URTI symptoms and resolution time

Answer 14

o Mean resolution: 2-3 days
o 75th percentile resolution: 7 days (cough up to 10 days)
o All symptoms subside within 2-3 weeks even without treatment

Question 15

Common cold

• Transmission
• Incubation period and shedding period
• Main mode of diagnosis

Answer 15

Transmission of the common cold:
o By contacts & droplets: Virus found in 40% hand sample, 10% cough/sneeze sample
o Maximum viral shedding on day 2 & day 3
o Natural infectivity rate 38-88%
o Median incubation 3 d (1-10)
o 70-90% infected are symptomatic

Clinical diagnosis only, investigations and serology not necessary

Question 16

General treatment outline for simple viral URTI

Answer 16

Conservative approach:
 Stress reduction, rest, adequate fluid
 Curative treatment is usually not needed

Symptomatic relief:

• Sore throat: Paracetamol and NSAID
• Cough and phlegm: antitussives, cough suppressants, expectorants, mucolytics, Inhaled beta agonists, antihistamines, decongestants
• Nasal symptoms: nasal decongestants, Topical ipratropium, heated humidified air

Novel treatments (not clinically effective)
 Vitamin C 1-3g: no benefit if taken at onset of illness
 Zinc within 2 days of onset:

Question 17

Treatment options for systemic aches and sore throat in viral URTI

Answer 17

 Paracetamol - effective & safe
 NSAID (ibuprofen) - more effective but more side effects (e.g. GI upset)
 Aspirin (salicylate) - contraindicated in children & influenza (Reye’s Syndrome)

 No large-scale quality trials on lozenges
 Steroids - AVOID

Question 18

Treatment options for cough and phlegm in viral URTI

Answer 18

No good evidence for the effectiveness of any over-the-counter cough medicine

Cough suppressant:

• Non-opioid (sedating antihistamines): Diphenhydramine (benadryl expectorant), dexbrompheniramine
• Opioid: Dextromethorphan, codeine, pholcodine

Expectorants:
 Ammonium chloride, e.g. MES (buffer)
 Ipecacuana, e.g. MES
 Guaifenesin, e.g. Robitussin
 Squill, e.g. Cocillana compound syrup

Mucolytic:
 Bromhexine
 Acetylcysteine

Inhaled/ oral beta agonist: prolonged (>1 week) cough in URI, with bronchial hypersensitivity

Antihistamine

Decongestant

Question 19

Treatment for nasal symptoms in viral URTI

Answer 19

• *No proven efficacy in children and adults for URI**
• *FDA warning: avoid in children <2yo (convulsion, tachycardia, death)**

1. Antihistamines: e.g. chlorphenamine (piriton) BEWARE OF OVERDOSE
2. Nasal decongestants, e.g. pseudoephedrine, phenylpropanolamine BEWARE OF HYPERTENSIVE COMPLICATIONS

Question 20

Combination preparations for URTIs

Risk of combination preparations

Answer 20

Antitussives, antihistamines, expectorants and decongestants

Risks: overdosing in children and associated with sudden infant deaths

Question 21

Prevention of common cold

Answer 21

Daily 8 hours sleep

• Participants with <7 hrs of sleep were 2.94 times more likely to develop a cold
• <92% sleep efficiency were 5.50 times more likely to develop a cold than those with >98% efficiency

Stress reduction

Hand hygiene

Question 22

Clinical criteria for ILI (influenza-like illness)

Answer 22

o Fever ≥38oC + cough and/or sore throat*
o Severe systemic upset
o Generalized myalgia
o Nasal symptoms mild

Question 23

Influenza

• Main mode of Dx
• Typical course
• Drug treatments

Answer 23

Clinical diagnosis - Rapid test not more accurate than clinical Dx

Typical course: Most cases are self-limiting; complications (mostly pneumonia) occur in 5-20%

Influenza drug treatment: Curative treatments are limited and usually unnecessary***
o Oral Oseltamivir (Tamiflu®)
o Inhaled Zanamivir (Relenza®)
o Intravenous Peramivir (Rapivab®): reduce complication
o Oral Baloxavir marboxil (Xofluza®)

Question 24

Vaccination options against influenza

Time lapse between vaccination and protection from serious illness

Answer 24

Effective 2 weeks post-vaccination in preventing illness, complications, hospitalization, death

Options:
Quadrivalent Influenza Vaccines - general use for aged 6 months or above
Live attenuated influenza vaccine (intranasal): Flumist - non-pregnant and non-immunocompromised people aged 2-49 years

Question 25

Priority groups for flu vaccine

Answer 25

Healthcare workers
Institutionalized persons (elderly care centres)
Age >50 (higher rates of ICU admission and death)

People with chronic medical problems:
 Chronic lung/ cardiovascular (except uncomplicated HT)/ renal/ metabolic diseases
 Obesity with BMI >30
 Immunocompromised
 All children and adolescents on long term aspirin
 People with chronic neurological condition that can compromise respiratory function or self-care ability or lead to increased risk of aspiration
 Children 6 months to 11 years
 Pregnant women (but not live attenuated vaccine)
 Poultry workers/ pig farmers/ pig slaughtering industry personnel