Seasonal lower respiratory tract infection of young children, typically caused by Respiratory syncytial virus (RSV) but can be others or mixed.
Classically wheezy cough, wheeze and/or crackles, reduced feeding and increased work of breathing.
Fever not usually high (“consider pneumonia if over 39”)
Diagnosis
Clinical. You would probably have to do 133 Chest x-rays before you found something that would change diagnosis – overuse of CXR associated with increased (and inappropriate) use of antibiotics.
Swabbing for virus identification can help with cohorting and avoidance of nosocomial infection, which can be a major problem.
Management
Ex-prems, chronic lung disease, neuromuscular disorders, haemodynamically significant congenital cardiac disease, immunodeficiency at higher risk, of course.
Admit if sats under 90% if 6/52+ (92% if underlying health problem or under 6/62) – and start oxygen if persistently low.
Admit if feeds less than 50-75% of usual volume, or severe respiratory distress, or reported/observed apnoeas.
NG or orogastric feeds if required – no preference but in theory obstructing nostrils could be unhelpful…
And UTI
Bacteriuria is not uncommonly seen with bronchiolitis, not always clear if this is true urine infection.
Prognosis
Initial coryza 1-3 days. Symptoms peak at 3-5 days. Cough resolves within 3 weeks in 90% but can persist for longer (but perhaps recurrent viruses?).
Prevention
RSV passive immunisation for high risk babies with paluvizimab (Synagis). Limited benefit but does appear to reduce incidence of severe bronchiolitis.
Vaccination in pregnancy effective – antibodies cross, but also prevents Mum getting it and passing it on!
There’s an important story about the dangers of vaccine development.
JCVI recommended Nirsevimab be used first line in 2023 – single injection (half life 71 days). HARMONIE trial – 83% reduction in RSV hospitalisation, 75% reduction in “very severe” disease. Spain and US doing. Fight for global supply so not available…
2025 – programme for high risk babies extended to include all babies born <32/40 (regardless of whether mum received vaccine in pregnancy).
Treatment
See here.