Resp - Virally Induced Wheeze Flashcards
Definition
Episodic wheeze - a symptom of viral URTI and common in preschool children up to 5 years old.
- Most common virus with wheezing in children include RSV, rhinovirus, and influenza viruses
Epidemiology
Under 5
Hereditary element
More likely to develop asthma later in life
Aetiology
RSV
Rhinovirus
Pathophysiology (clue: similar to bronchiolitis)
Children have small airways
When encounter virus - leads to inflammation and oedema
Swelling of airways restricts space for airflow
Inflammation also triggers smooth muscles of airways to constrict = even more narrow
Air flowing through these narrow airways causes wheeze = restricted ventilation = respiratory distress
3 defining factors of virally induced wheeze
Presenting before 3 years of age
No atopic history
Only occurs during viral infections
Signs and symptoms
Evidence of a viral illness (fever, cough and coryzal symptoms) for 1-2 days preceding the onset of:
Signs:
- Tachypnoea
- Widespread wheeze on auscultations
- Respiratory distress
- Evidence of URTI e.g hyperaemic tonsils
Symptoms:
- Coryza
- Cough and wheeze
- Difficulty in breathing
- Poor feeding
- Fever
Shortness of breath
Signs of respiratory distress
Expiratory wheeze throughout the chest
NEITHER VIW OR ASTHMA CAUSES FOCAL WHEEZE
THINK:
- FOCAL AIRWAY OBSTRUCTION
- TUMOUR
Diagnosis
Clinical diagnosis
Investigations to consider:
- PEFR
- Chest X ray
- Capillary blood gas
Management
Oxygen
Bronchodilators:
- FIRST LINE = SABA
- SECOND LINE = Antimuscarinic e.g. ipatropium bromine
Ventilation
Prevention in children with recurrent wheeze
Corticosteroids
- trial of Inhaled corticosteroids considered when there is FHx of asthma
- trial of oral corticosteroids considered when child has had episode requiring admission
Leukotriene antagonists: MONTELUKAST
Complications
Respiratory failure
Asthma
