Upper Respiratory Tract Infections Flashcards
What is the most common cause of URTIs
Viruses
What are the most common type of common cold
Rhinoviruses
How are rhinoviruses transmitted
Inhaling droplets from sick people sneezing, coughing, or blowing nose
Touching contaminated surface then eyes nose or mouth
How long is the usual incubation time for a rhinovirus
1-5 days
How do viruses act on upper respiratory tract cells
Bind -> release genetic material into cell -> genetic material replication and protein transcription -> packaging into viruses -> new viruses released
Rhinorrhea
Excess mucus filling nasal cavity
What is nasopharyngitis usually referred to as
Common cold
2 main common cold symptoms
Rhinorrhea
Nasal obstruction
Which receptors on airway epithelial cells recognise human rhinovirus and respiratory syncytial virus
Toll like receptors
Retinoic acid inducable gene-1-like receptors
What do airway epithelial cells do when human rhinovirus infection or respiratory syncytial virus binds
Release pro inflammatory mediators causing recruitment + activation of inflam and immune cells and immune respinse
How do URTIs cause Rhinorrhea and nasal obstruction
Neutrophilic inflammation increases vascular permeability and mucus hypersecretion
How do viruses impede immune recognition
High glycosylation
Structural variability of surface G protein
Release of soluble G protein ‘decoy’
How does release of soluble G proteins from viruses impede immune recognition
Virus specific antibodies bind to released G proteins instead of virus
Why are asthma patients more susceptible to HRV infection
Incr cytokines release
Incr intracellular adhesion molecule
What do viral infections commonly cause in asthma and COPD patients
Exacerbations
What do frequent acute exacerbations of COPD lead to
Worsening symptoms
Increased disease progression
Increased hospitalisation
Increased airway inflammation
Worsening hyperinflation
Lung function decline
Death
How is virus infection risk decreased
Wash hands
A valid touching face
Disposable tissues
Hand sanitiser
PPE
How long does nasopharyngitis last, and how long is it symptomatic
Lasts up to 2wks
Symptomatic 7-11 days
How can nasopharyngitis be treated
Nasal/systemic steroids
Nasal irrigation
Antibiotics
Decongestants
Mucolytics
How do decongestants work
Cause vasoconstriction in blood vessels around nasal sinuses
What is the mechanism of decongestants
Alpha 1 adrenoreceptor agonists
Which features are involved in FeverPAIN score
Fever
Purulence
Attend within 3 days or less
Severely inflamed tonsils
No cough or coryza
What characteristics are involved in Centor score
Tinsilkar exudate
Tender anterior cervical lymphadenopathy or lymphadenitis
History of fever
No cough
What are the 2 scored sore throat assessments
FeverPAIN score
Centor score
What is a backup antibiotic prescription
Patient given slip to get antibiotics only if needed / symptoms not improved in certain timeframe
What FeverPAIN score should a backup antibiotic be considered, but not an immediate antibiotic
2 or 3
What FeverPAIN or Centor scores should an immediate or backup antibiotic prescription be considered
FeverPAIN 4/5
Centor 3/4
When should a URTI patient be given an immediate antibiotic prescription
Systemically very unwell
Symptoms and signs of more serious condition
High risk of complications
First choice antibiotic for sore throat
Phenoxymethylpenicillin
Which antibiotics could be given to a sore throat patient with a penicillin allergy
Clarithromycin
Erythromycin
What condition is known as the common cold
Nasopharyngitis
What do HRV and RSV cause
Nasopharyngitis
