Viral induced wheeze

Question 1

What is usually the cause of wheeze in children 1-5 years (preschool age)?

Answer 1

Viral episodic wheeze

Question 2

What is thought to be the cause of viral episodic wheeze?

Answer 2

small airways being more likely to narrow and obstruct due to inflammation and aberrant immune responses to viral infection

Question 3

Why is it referred to as viral episodic wheeze?

Answer 3

triggered by viruses that cause the common cold

Question 4

What have studies shown is present in many sufferers of viral episodic wheeze?

Answer 4

sufferers often have reduced small airway diameter from birth

Question 5

What are 3 risk factors for viral episodic wheeze?

Answer 5

1. Maternal smoking during and/or after pregnancy
2. Prematurity
3. Family history of early viral wheezing - not family history of asthma or allergy

Question 6

In which gender is viral episodic wheeze more common?

Answer 6

males

Question 7

What age is affected by viral episodic wheeze?

Answer 7

1- 5 years (under 1, i.e. 1-9 months = bronchiolitis, >5y = asthma)

Question 8

What is thought to cause the resolution of viral episodic wheeze by age 5?

Answer 8

presumed to be due to increase in airway size

Question 9

What are 3 additional causes of wheeze (additional to bronchiolitis, asthma and viral episodic)?

Answer 9

1. Atypical pneumonia
2. Foreign body inhalation
3. Anaphylaxis

Question 10

What are 3 causes of atypical pneumonia which may cause wheeze?

Answer 10

1. Mycoplasma
2. Chlamydia
3. Adenovirus

(pneumococcal pneumonia doesn’t generally cause it)

Question 11

What is the likely presentation of foreign body inhalation as a cause of wheeze?

Answer 11

abrupt onset of cough followed by wheeze in previously well child

Question 12

What is likely to be the anatomical course of an inhaled foreign body?

Answer 12

on passing below the glottis, usually impacts in main or lobar bronchus, may initially cause unilateral wheezing and air trapping

Question 13

What will be present on examination in foreign body inhalation causing wheeze?

Answer 13

unilateral wheeze, air trapping (Reduced air entry in one area)

Question 14

What investigation should be performed in suspected foreign body inhalation as a cause of wheeze and what will it show?

Answer 14

Chest x-ray performed during expiration: persistent hyperinflation of lung distal to obstruction

eventually airway swelling causes complete obstruction and lobar collapse is seen

Question 15

What are 4 things that should make you suspect anaphylaxis as a cause of wheeze?

Answer 15

1. Acute urticaria
2. Facial swelling
3. Stridor
4. Previous reaction to an allergen