Upper respiratory tract infections Flashcards
What pathogen usually causes the common cold?
Rhinoviruses
What is the official name for a common cold?
Acute coryza
What is the incubation period for rhinoviruses?
12 hours to 5 days
What are the symptoms of a common cold?
Malaise
Slight pyrexia
Sore throat
Nasal discharge
What is sinusitis?
Inflammation of the nasal sinuses, usually caused by infection
What pathogens usually cause sinusitis?
Rhinoviruses
Streptococcus pneumonia
Haemophilus influenzae
What are the symptoms of sinusitis?
Frontal headache Facial pain Tenderness Nasal discharge Malaise
What is rhinitis?
Sneezing attacks, nasal discharge and/or blockage
occurring for more than 1 hour on most days
What two types of rhinitis are there? How can you distinguish them?
Seasonal rhinitis:
Occurs during summer months, caused by allergy to pollen
Symptoms of eye and soft palate itching
Perennial rhinitis:
May or may not be allergic
No symptoms affecting eye or soft palate
Distinguish:
Is it seasonal?
Are the eyes and soft palate itchy?
What can occur as a result of perennial rhinitis?
Nasal polyps can form, which can cause nasal obstruction, loss of smell and taste and mouth breathing
How do you diagnose rhinitis?
Skin prick test: look for allergens
Measure levels of IgE against causal antigens
How would you manage rhinitis?
Avoidance of allergen
Anti-histamines
Decongestants
Topical steroids, oral if all else fails
What is pharyngitis?
Inflammation of the pharynx, usually caused by infection.
What pathogens usually cause pharyngitis?
Mostly viruses, particularly adenoviruses
Secondary invasion by bacteria:
H. influenzae
Streptococcus
Staph. aureus
What are the symptoms of pharyngitis?
Sore throat
Fever
Malaise
In a case of pharyngitis, how would you know if secondary invasion has occurred?
If the infection has not gone away of its own accord, then suspect secondary invasion by bacteria
How would you treat pharyngitis?
Treat symptoms initially
If no improvement (the infection has gone by self-limiting) treat with antibiotics (penicillin)
Croup is another name for…
Acute laryngotracheobronchitis
What pathogens usually cause croup?
Parainfluenza virus
Measles virus
Which type of people suffer worst when they get croup?
Children under the age of 3
What are the symptoms of croup?
LARYNX
Hoarse voice
Barking cough
Stridor (grating sound on inhalation)
TRACHEA
Burning retrosternal pain
What is it that causes the hoarse voice, barking cough + stridor in croup?
Inflammatory oedema of the larynx
How do you treat croup?
Oxygen
Oral or intramuscular corticosteroids
Nebulised adrenaline
Rarely, intubation or tracheotomy is necessary
What types of influenza virus are there?
A, B and C
What are the surface antigens that are found on the surface of influenza viruses?
Haemagglutinin
Neuraminidase
What does haemagglutinin do to help the influenza virus?
Binds to the host cells and gains entry
What does neuraminidase do to help the influenza virus?
Gets viruses out of cells once they are newly produced
Which is more virulent, influenza A, B or C?
A
Which is able to cause pandemics, influenza A, B or C?
A
Which causes sporadic outbreaks in institutions like schools and garrisons, influenza A, B or C?
B
Which can cause an infection that is asymptomatic, influenza A, B or C?
C
How long is the incubation period for influenza viruses?
About 1-3 days
What are the symptoms of flu?
How long can they last?
Abrupt onset of fever Generalised aching of limbs Severe headache
Sore throat
Dry cough
Can last for several weeks
How do you diagnose flu?
You don’t usually
But you would see a rise in antibody levels if you did serology
Management of flu?
Symptomatic treatment:
Paracetamol, bed rest, fluids
Prevention of secondary infection in susceptible people
What complications can arise from flu?
Pneumonia
Who is susceptible to secondary infection after getting flu?
People with lung problems
People with heart or renal failure
Which people are at a higher risk of mortality from flu?
Chronic cardiac and pulmonary disease
Old age
Renal disease
Immunosuppressed
What is an outbreak?
2 or more linked cases
What is an epidemic?
Lots of cases in a region or country
What is a pandemic?
An epidemic that spans international boundaries
What is antigenic drift?
Every year, the virus changes its antigens slightly which means people are no longer immune to it
