Respiratory Tract Infections

Question 1

List the infections of the upper respiratory tract.

Answer 1

• Rhinitis
• Pharyngitis
• Laryngitis
• Tonsillitis
• Otitis media
• Mastoiditis
• Sinusitis

Question 2

List the infections of the airway.

Answer 2

• Croup
• Epiglottitis

Question 3

List the infections of the lower respiratory tract.

Answer 3

• Bronchiolitis
• Pneumonia

Question 4

List respiratory viral infections and their symptoms.

Answer 4

• Other causative agents of viral infections:
  
  • Adenovirus
  • Coronavirus
  • Metapneumovirus
  • Parainfluenza
  • Rhinovirus

Question 5

Describe the common cold, its causative agents, transmission, clinical picture and investigation.

Answer 5

• An infection of the upper resiratory tract.
• Commonest infection of childhood.
• Seasonal: early autumn and mid/late spring.
• Causative agents:
  
  • ​40% rhinovirus (>100 serotypes)
  • 30% coronaviruses (>3 serotypes)
  • Enterovirus
  • Parainfluenza virus
• Transmission:
  
  • ​Aerosol and virus-contaminated hands.
• Clinical:
  
  • ​Slight pyrexia
  • Malaise
  • Sneezing in early stages
  • Profuse, watery nasal discharge
  • Sore nose and pharynx
  • Seconday bacterial infection occurs in minority
• Investigation
  
  • ​NONE

Question 6

Describe how to communicate with a patient who has the common cold.

Answer 6

• Reassure the person or carer that although symptoms may be distressing, the common cold is self-limiting and complications are rare.
• No treatments are available that can cure the common cold and most treatments are not effective at relieving symptoms.
• Explain that symptom relief and rest are the most appropriate management.
• Advise people that:
  
  • Antibiotics and antihistamines are ineffective and may cause adverse effects.
  • Adequate fluid should be taken during the course of the illness.
  • Healthy food is recommended, although no specific diet or mineral or vitamin supplement is necessary.
  • Adequate rest is advised - although staying off work or school is normally not necessary. Normal activity will not prolong the illness.

Question 7

Describe pharyngitis, its aetiology, clinical presentation and management.

Answer 7

• Sore throat. Common.
• Aetiology:
  
  • Usually due to viral infection with respiratory viruses (mostly adenoviruses, coronaviruses, enteroviruses and rhinoviruses).
• Clinical:
  
  • The pharynx and soft palate are inflamed and local lymph nodes are enlarged and tender.
• Management:
  
  • Symptomatic

Question 8

What is tonsillitis?

Answer 8

Tonsillitis is a form of pharyngitis where there is intense inflammation of the tonsils.

Question 9

Describe the aetiology of tonsillitis.

How is it transmitted?

Answer 9

• 50-80% of infective sore throat is of a viral cause.
• An additional 1-10% of cases are caused by Epstein-Barr virus (glandular fever).
• The most common bacterial organism identified is group A β-haemolytic streptococcus (GABHS), which causes 5-36% of infections.
• Transmission is by airborne droplets and contact.

Question 10

Describe the presentation of a patient with GABHS tonsillitis.

Answer 10

• This is the most common bacterial pathogen, for which antibiotic treatment may be considered.
• Tonsilar exudate
• Tender anterior cervical lymph nodes
• History of fever
• Absence of cough

Question 11

Describe the factors to be considered in diagnosing tonsillitis.

Answer 11

• A positive throat culture for GABHS makes the diagnosis of streptococcal sore throat likely but a negative culture does not rule out the diagnosis.
• The asymptomatic carrier rate for GABHS is up to 40%.
• Throat swab culture cannot differentiate between the streptococcal carrier state and invasive infection.

Question 12

Describe the considerations when treating tonsillitis with antibiotics.

Answer 12

• The superiority of antibiotics over simple analgesics is marginal in reducing duration or severity of symptoms.
• Even in proven GABHS infection, the symptomatic improvement following penicillin, although superior to that following placebo in some studies, has been unimpressive in others, especially when compared to simple analgesics.
• In severe cases, where the practitioner is concerned about the clinical condition of the patient, antibiotics should not be withheld.
• Penicillin V 500mg four times daily for 10 days is the dosage used most frequently.
• A macrolide can be considered as an alernative first-line treatment, in line with local guidance.

Question 13

What is the primary clinical rationale for treating streptococcal pharyngitis with antibiotics?

Answer 13

• The primary clinical rationale for treating streptococcal pharyngitis with antibiotics is the prevention of rheumatic fever and other sequelae.
• The incidence of rheumatic fever in the UK is extremely low and there is no support in the literature for the routine treatment of sore throat with penicillin to prevent the development of rheumatic fever.
• Similar considerations apply to the prevention of glomerulonephritis.

Question 14

What is poststreptococcal glomerulonephritis (PSGN)?

Answer 14

• Poststreptococcal glomerulonephritis (PSGN) is caused by prior infection with specific nephritogenic strains of group A β-haemolytic streptococcus.
• Antibodies to bacteria cross react with the host.

Question 15

Describe the clinical presentation of poststreptococcal glomerulonephritis (PSGN).

Answer 15

• The clinical presentation of PSGN varies from asymptomatic, microscopic haematuria to the full acute nephritic syndrome, characterised by red to brown urine, proteinuria (which can reach the nephrotic range), oedema, hypertension and acute kidney injury.
• The prognosis is generally favourable, especielly in children, but in some cases the long-term prognosis is not benign.

Question 16

What is otitis media?

Answer 16

Infection of the cavity of the middle ear.

Question 17

Describe the incidence and aetiology of acute otitis media.

Answer 17

• Incidence
  
  • 75% of children will have at least one episode of acute otitis media before they are 5.
  • This is most common at 6-12 months.
• Aetiology:
  
  • Viruses
    
    • RSV
    • Rhinovirus
  • Bacteria
    
    • Streptococcus pneumoniae and haemophilus influenzae are responsible for up to 80% of bacterial acute otitis media.

Question 18

Describe the clinical features of otitis media.

Answer 18

• Symptoms
  
  • Fever
  • Pain
  • D&V
• Signs
  
  • Bulging ear drum and dilated vessels

Question 19

Describe the diagnosis of acute otitis media.

Answer 19

• Diagnosis is clinical: an auroscope may show fluid levels, an inflammed tympanic membrane or a purulent discharge associated with perforation.

Question 20

Describe the course of acute otitis media.

Answer 20

• It lasts for about a week, and most get better in 3 days without antibiotics.
• Serious complications are rare.
• Ear infection may be complicated by perforation, recurrent or chronic infection or the development of ‘glue ear’ (sterile mucous within the middle ear.

Question 21

Describe otitis media with effusion.

Answer 21

• Recurrent ear infections can lead to otitis media with effusion.
• Otitis media with effusion is very common between the ages of 2 and 7 years, with peak incidence between 2.5 and 5 years.
• Clinical presentation:
  
  • Possible decreased hearing.
  • Eardrum is seen to be dull and retracted, often with a fluid level visible.
• Cochrane reviews have shown no evidence of long-term benefit from the use of antibiotics, steroids or decongestants.

Question 22

Describe the management of otitis media with effusion.

Answer 22

• Active observation over 6-12 weeks is appropriate for most children, as spontaneous resolution is common.
• Re-evaluate signs and symptoms of the effusion and concerns regarding the child’s hearing or language development.
• Ideally, this should include 2 hearing tests.
• Grommets - improves hearing short-term, but has not been shown to improve other aspects of development.
• Adjuvant adenoidectomy is not recommended in the absence of persistent and / or frequent upper respiratory tract symptoms.

Question 23

What is sinusitis?

Answer 23

• Infection of the paranasal sinuses may occur with viral URTIs.
• Occasionally there is secondary bacterial infection, with pain, swelling and tenderness over the cheek from infection of the maxillary sinus.

Question 24

Describe the aetiology of sinusitis.

Answer 24

• S. pneumoniae
• H. influenza
• S. milleri
• Mucosal swelling prevents muco-cilliary clearance of infection.
• Blockage of the eustachian tube or sinuses.

Question 25

Describe the clinical presentation of sinusitis.

Answer 25

Pain and headache over the affected sinus, usually maxillary and frontal.

Question 26

What investigations would be done to diagnose sinusitis.

Answer 26

• Usually none
• But, x-ray would show thickening of the soft tissue of the cavity +/- fluid level.

Question 27

Describe the management of a patient with sinusitis.

Answer 27

• Antibiotics and analgesia are used for acute sinusitis in addition to topical decongestants.
• Ampicillin, amoxycillin and oral cephalosporins.
• There is some recent evidence that the concurrent use of intranasal corticosteroids or antihistamines together with antibiotics hasten recovery.

Question 28

What are the differentials for stridor?

Answer 28

• Acute:
  
  • Viral laryngotracheobronchitis (croup)
  • Epiglottitis
  • Bacterial tracheitis
  • Retropharyngeal abscess
• Non-infectious
  
  • Angiodema
  • Foreign body
• Chronic
  
  • Congenital
    
    • ​Laryngomalacia
    • Vascular ring
    • Laryngo or tracheal web, cyst or haemangioma
  • Acquired
    
    • ​Post-traumatic tracheal stenosis
    • Mediastinal mass e.g. tumour

Question 29

What is laryngotracheobronchitis?

Describe its incidence and aetiology.

Answer 29

• Infection of the laryngotracheabronchial airway.
• Incidence:
  
  • 3 months to 6 years of age but the peak incidence is in the second year of life.
  • It is commonest in the autumn.
• Aetiology:
  
  • 95% viral-parainfluenza RSV and influenza, can produce a similar clinical picture.

Question 30

Describe what happens in laryngotracheobronchitis.

Answer 30

• There is mucosal inflammation and increased secretions affecting the airway, but it is the oedema of the subglottic area that is potentially dangerous in young children because it may result in critical narrowing of the trachea.
• The typical features are a barking (seal bark) cough, harsh stridor and hoarseness, usually preceded by fever and coryza.
• The symptoms often start, and are worse, at night.

Question 31

Categorise the severity of symptoms in croup.

Answer 31

• Mild - seal-like barking cough but no stridor or sternal / intercostal recession at rest.
• Moderate - seal-like barking cough with stridor and sternal recession at rest; no agitation or lethargy.
• Severe - seal-like barking cough with stridor and sternal / intercostal recession associated with agitation or lethargy.
• Impending respiratory failure - increasing upper airway obstruction, sternal / intercostal recession, pallor or cyanosis, decreased level of consciousness.
  
  • The degree of chest wall recession may diminish with the onset of respiratory failure as the child tires.

Question 32

What should be considered when thinking about hospital admission of a patient with croup?

Answer 32

• Admit all children with features of moderate or severe illness, or impending respiratory failure.
• Hospital admission should also be considered for children with a respiratory rate of over 60 breaths / minute.
• Children with mild illness may require admission if they have factors that warrant a lower threshold for admission, such as:
  
  • Age under 3 months
  • Inadequate fluid intake (50-75% of usual volume, or no wet nappy for 12 hours)

Question 33

Describe the pre-hospital treatment for a child with moderate croup.

Answer 33

• Prescribe a single dose of oral dexamethasone (0.15mg/kg) to be taken immediately.
• Advise the parents / carers about the expected course of croup, including that symptoms usually resolve within 48 hours.

Question 34

Describe the pre-hospital treatment for a child with severe croup.

Answer 34

• Oxygen if symptoms of severe illness or impending respiratory failure.
• Administer a dose of oral dexamethasone (0.15mg/kg).
• If the child is too unwell to receive medication, inhaled budesonide (2mg nebulised as a single dose) or intramuscular dexamethasone (0.6mg/kg as a single dose) are possible alternatives.

Question 35

What is epiglottitis?

What causes it?

Answer 35

• Acute epiglottitis is a life-threatening emergency due to the high risk of respiratory obstruction.
• There is intense swelling of the epiglottis and surrounding tissues associated with septicaemia.
• Epiglottitis is most common in children aged 1-6years but affects all age groups.
  
  • It is important to distinguish clinically between epiglottitis and croup.
• It is caused by H. influenzae type b.
• In the UK and many other countries, the introduction of universal Hib immunisation in infancy has led to a >99% reduction in the incidence of epiglottitis and other invasive H. influenzae type b infections.

Question 36

Compare and contrast croup and epiglottitis.

Answer 36

Question 37

Describe the clinical presentation of epiglottitis.

Answer 37

• High fever in an ill, toxic-looking patient.
• An intensely painful throat that prevents speaking or swallowing; saliva drools down the chin.
• Soft inspiratory stridor and rapidly increasing respiratory difficulty over hours.
• The patient will sit immobile, upright, with an open mouth to optimise airway.

Question 38

Describe the diagnosis and treatment of a patient with acute epiglottitis.

Answer 38

• Diagnosis:
  
  • DO NOT examine the throat or take throat swabs as this will precipitate complete obstruction of the airway.
  • Blood cultures to isolate H. influenzae.
• Treatment:
  
  • Life-threatening emergency.
  • Requires urgent endotracheal intubation.
  • Intravenous antibiotics (ceftriaxone).

Question 39

What is tracheitis?

Answer 39

• Infections may spread down from the URT.
• Usually viral origin
  
  • Parainfluenza virus
  • Respiratory syncytial virus
  • Influenza virus
  • Adenovirus
• In adults: hoarseness; retrosternal pain
• In children: dry cough, inspiratory stridor (croup)

Question 40

Describe the aetiology and epidemiology of bronchiolitis.

Answer 40

• The commonest serious infection of infancy: 2-3% of all infants are admitted to hospital with the disease each year during annual winter epidemics.
• 90% are aged 1-9 months (bronchiolitis is rare after 1 year of age).
• Respiratory syncytial virus (RSV) is the pathogen in 80% of cases.
• The remainder are accounted for by adenovirus, influenza virus, human metapneumovirus, parainfluenza virus, rhinovirus and mycoplasma pneumoniae.

Question 41

Describe the clinical presentation of bronchiolitis.

Answer 41

• Coryzal symptoms precede a dry cough and increasing breathlessness.
• Feeding difficulty associated with increasing dyspnoea is often the reason for admission to hospital.
• Recurrent apnoea is a serious complication, especially in young infants.
• Infants born prematurely or with other underlying lung disease, such as CF, or have congenital heart disease, are most at risk from severe bronchiolitis.
• Laboured breathing.
• Increased work of breathing is judged by:
  
  • Nasal flaring
  • Expiratory grunting - to increase positive end-expiratory pressure.
  • Use of accessory muscles, especially SCMs.
  • Retraction (recession) of the chest wall, from use of suprasternal, intercostal and subcostal muscles.
  • Difficulty speaking (or feeding).

Question 42

Under what circumstances should a child with bronchiolitis be referred?

Answer 42

• Immediately refer children with bronchiolitis for emergency hospital care (usually by 999) if they have any of the following:
  
  • Apnoea (observed or reported).
  • Child looks seriously unwell to a healthcare professional.
  • Severe respiratory distress, for example grunting, marked chest recession, or RR >70 breaths per minute.
  • Central cyanosis.
  • Persistent oxygen saturation of less than 92% when breathing air.
• Consider referring children with bronchiolitis to hospital if they have any of the following:
  
  • RR >60 breaths per minute.
  • Difficulty with breastfeeding or inadequate oral fluid intake (50-75% of usual volume, taking account of risk factors and using clinical judgement).
  • Clincal dehydration.

Question 43

Describe the investigations used in bronchiolitis

Answer 43

• Respiratory viruses are now usually identified by PCR analysis of nasopharyngeal secretions.
• A chest X-ray is unnecessary in straightforward cases, but if performed, typically shows hyperinflation of the lungs due to small airways obstruction, air trapping.

Question 44

Describe the management of bronchiolitis.

Answer 44

• This is supportive and escalated as required.
• Humidified oxygen is delivered via nasal canulae; the concentration required is determined by pulse oximetry.
• The infant is monitored for apnoea.
• Mist, antibiotics, steroids and nebulised bronchodilators, such as salbutamol or ipratropium, have not been shown to reduce the severity or duration of the illness.
• Fluids may need to be given by nasogastric tube or IV.
• Assisted ventilation in the form of nasal or facemask CPAP or full ventilation is required in a small percentage of infants admitted to hospital.
• RSV is highly infectious, and infection control measures, particularly good hand hygiene, are needed to prevent cross-infection to other infants in hospital.

Question 45

Describe the aetiology of penumonia.

Answer 45

• Caused by a variety of viruses and bacteria, although in over 50% of cases no causative pathogen is identified.
• Viruses are the most common cause in younger children, while bacteria are commoner in older children.
• In clinical practice it is difficult to distinguish between viral and bacterial pneumonia.
• The pathogens causing pneumonia vary according to the child’s age.

Question 46

In children with pneumonia, the pathogens vary according to the child’s age. What are the differences between newborns, infants and younger children, and children over 5 years?

Answer 46

• Newborn
  
  • ​Organisms from the mother’s genital tract, particularly group B streptococcus, but also gram negative enterococci.
• Infants and young children
  
  • ​Respiratory viruses, particularly RSV, are most common, but bacterial infections include streptococcus pneumoniae or haemophilus influenzae.
  • Bordetella pertussis and chlamydia trachomatis can also cause pneumonia at this age.
  • An infrequent but serious cause is staphylococcus aureus.
• Children over 5 years
  
  • ​Mycoplasma pneumoniae, streptococcus pneumoniae and chlaydia pneumoniae are the main causes.
• At all ages myobacterium tuberculosis should be considered.

Question 47

What are the presenting symptoms of pneumonia?

Answer 47

• Symptoms
  
  • ​Fever and difficulty breathing are the commonest presenting symptoms, usually preceded by an URTI.
  • Cough
  • Lethargy
  • Poor feeding
  • ‘Unwell’ child
• Localised chest, abdominal, or neck pain is a feature of pleural irritation and suggests bacterial infection.

Question 48

Describe the management of pneumonia in children.

Answer 48

• General supportive care should include oxygen for hypoxia and analgesia if there is pain.
• IV fluids should be given if necessary, to correct dehydration and maintain adequate hydration and salt balance.
• Physiotherapy has no role.
• The choice of antibiotic is determined by the child’s age, severity of illness and appearance on CXR.
• Newborns require broad-spectrum IV antibiotics.
• Most older infants can be managed with oral amoxicillin, with broader-spectrum antibiotics sich as co-amoxiclav being reserved for those who are complicated or unresponsive.
• For children >5 years of age, either amoxicillin or an oral macrolide such as erythromycin is the treatment of choice.

Question 49

What is the prognosis for children with pneumonia?

Answer 49

• Follow-up is not generally required for children with simple consolidation on CXR and who recover clinically.
• Those with evidence of lobar collapse, atelectasis or empyema should have a repeat CXR after 4-6 weeks.
• Virtually all children with pneumonia, even those with empyema, make a full recovery.