22. Upper respiratory tract infections

Question 1

Describe the upper respiratory tract

Answer 1

This includes the nose, paranasal sinuses, middle ear, nasopharynx, oropharynx, laryngopharynx, tonsils and adenoids

All of this is colonised by a variety of flora

Question 2

What are some common infections of the upper respiratory tract?

Answer 2

Colds
Pharyngitis i.e. core throat
Tonsilitis 
Sinusitis 
Otitis media (middle ear infection)

These are mainly caused by viruses

Question 3

Give the name of some viral pathogens

Answer 3

Adenovirus
Parainfluenza virus
Respiratory syncytial virus
Rhinovirus

Question 4

Describe ‘colds’ as URTIs

Answer 4

These are caused by numerous strains of rhinoviruses
Often preceded by a sore throat, sometimes accompanied by a fever and often followed by an opportunistic bacterial infection

Can lead to otitis media (middle ear infection) in children and sinusitis in adults

Question 5

Briefly describe rhinoviruses and how they can present clinically

Answer 5

Over 100 serotypes
Responsible for 50% of common colds

Incubation period is short - 1 to 3 days followed by headache, sore throat, blocked nose
Watery discharge from the nose
Infection resolves in about a week

Question 6

Following a cold, is the patient then immune to the rhinovirus?

Answer 6

Following a rhinovirus cold, there is a short period of immunity to all colds

There is also prolonged immunity to the specific serotype causing the recent infection

Question 7

What is pharyngitis?

Answer 7

This is an inflammation of the pharynx - generally due to a group A strep infection

Commonly known as a sore throat

Question 8

What are the clinical features of pharyngitis?

Answer 8

Incubation period of 2-3 days
Sore throat, fever, feel ill, 
Tender cervical nodes
Can lead to quincy
May occasionally lead to scarlet fever

Question 9

What is quincy?

Answer 9

Inflammation of the throat

May be an abscess in the region of the tonsils

Question 10

How can pharyngitis be diagnosed and treated?

Answer 10

Send throat swab for bacterial culture
Serology

Treated with antibiotics

Question 11

What is otitis media and how is it treated?

Answer 11

Middle ear infection due to viruses e.g. stretpcoccus phyogenes, streptococcus pneumoniae, haemophilus influenza

Generally occurs in children and is much less common in adults

Treated with antibiotics

Question 12

What is sinusitis and how is it treated?

Answer 12

Inflammation of a nasal sinus

Can be due to viral infection such as those causing otitis media or due to bacterial infection e.g. streptococcus pneumomniae

Treatment is not always necessary in this instance -dependant on the patient

Question 13

What is epiglottitis and how is it treated??

Answer 13

This is an inflammation of the epiglottis (prevents food from entering the trachea) - almost always bacteraemic

Can lead to rapid onset of respiratory obstruction - a CT scan/lateral x-ray can show swelling of the soft tissues in the neck

This is a medical emergency - tracheostomy, antibiotics, prophylaxis

Question 14

What is the ‘Epstein Barr Virus’?

Answer 14

EBV - causes glandular fever
Causes a systemic disease but this usually presents as a sore throat

Can present as pharyngeal and tonsillar swelling and also often get enlargement of the spleen and the liver

Question 15

What is ‘Respiratory syncytial virus’?

Answer 15

RSV - single major pathogen in respiratory conditions in childhood

Causes a localised infection of the respiratory tract - infants have no maternal passive protection

Question 16

Give the mechanism of a viral infection

Answer 16

Viruses are intracellular parasites

Binds to the surface of the cell and enters the cell cytoplasm
Then release the viral genome into the cell for replication
Viral proteins are then produced and progeny virus particles are formed and released
These go on to infect further host cells