Bronchiolitis

Bronchiolitis is a condition characterised by acute bronchiolar inflammation. Respiratory syncytial virus (RSV) is the pathogen in 75-80% of cases. NICE released guidelines on bronchiolitis in 2015. Please see the link for more details.

Epidemiology

• most common cause of a serious lower respiratory tract infection in < 1yr olds (90% are 1-9 months, with a peak incidence of 3-6 months). Maternal IgG provides protection to newborns against RSV
• higher incidence in winter

Basics

• respiratory syncytial virus (RSV) is the pathogen in 75-80% of cases
• other causes: mycoplasma, adenoviruses
• may be secondary bacterial infection
• more serious if bronchopulmonary dysplasia (e.g. Premature), congenital heart disease or cystic fibrosis

Features

• coryzal symptoms (including mild fever) precede:
• dry cough
• increasing breathlessness
• wheezing, fine inspiratory crackles (not always present)
• feeding difficulties associated with increasing dyspnoea are often the reason for hospital admission

NICE recommend immediate referral (usually by 999 ambulance) 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 a respiratory rate of over 70 breaths/minute
• central cyanosis
• persistent oxygen saturation of less than 92% when breathing air.

NICE recommend that clinicians 'consider' referring to hospital if any of the following apply:

• a respiratory rate of over 60 breaths/minute
• difficulty with breastfeeding or inadequate oral fluid intake (50-75% of usual volume 'taking account of risk factors and using clinical judgement')
• clinical dehydration.

Investigation

• immunofluorescence of nasopharyngeal secretions may show RSV

Management is largely supportive

• humidified oxygen is given via a head box