RSV & Bronchiolitis in Babies — Irish Parent Guide

What is RSV bronchiolitis?

Respiratory Syncytial Virus (RSV) is the most common cause of bronchiolitis — an inflammation of the small airways (bronchioles) in babies. It is the leading cause of hospital admission for respiratory illness in Irish under-1s, peaking in autumn and winter. Almost all children will have had at least one RSV infection by age 2.

In older children and adults, RSV usually causes only cold-like symptoms. In babies — particularly under 6 months — the small airways become inflamed and clogged with mucus, making feeding and breathing harder work.

Typical course

• Days 1-3: cold-like symptoms — runny nose, mild cough, sometimes mild fever
• Days 3-5: cough becomes worse; wheeze may appear; faster breathing; feeding difficulty
• Days 5-7: typically the most difficult phase
• Days 7-14: gradual improvement; cough may persist for 2-3 weeks

Most babies recover at home with supportive care.

When to seek same-day or emergency care

Call 999/112 or attend emergency immediately for any of these red flags per NICE CKS:

• Severe difficulty breathing — sucking in at the ribs, neck, or above the breastbone
• Breathing very fast or grunting with each breath
• Pauses in breathing (apnoeas)
• Bluish lips, tongue, or face
• Very floppy, unresponsive, or extremely drowsy
• Unable to feed (taking less than half normal feeds for 2-3 feeds)
• Dry nappies for over 12 hours (dehydration)

Seek same-day in-person review if your baby:

• Is under 3 months old with any concern about breathing
• Is breathing faster than usual or working harder to breathe
• Has high fever
• Has reduced feeds (but not severely)
• Was born premature or has chronic lung/heart conditions
• Is generally unwell in a way that concerns you

Home management for mild bronchiolitis

• Smaller, more frequent feeds — your baby may tire halfway through a feed
• Keep your baby upright when feeding
• Saline nasal drops before feeds can help clear blocked noses
• Paracetamol (age-appropriate paediatric dose) if febrile and uncomfortable — only for babies over 2 months and follow product labelling carefully
• No smoking in the home
• Monitor breathing and feeding

Important: cough/cold over-the-counter medications are not safe for under-6s. Honey is not safe for under-1s. Steroids and bronchodilators (inhalers) are generally not effective for bronchiolitis — different from asthma.

Prevention

• Hand washing — single most effective measure
• Avoid sick contacts where possible, particularly in the first 3 months
• Breastfeeding provides some protective benefit
• Avoid smoke exposure
• Nirsevimab (Beyfortus) — passive immunisation now offered to eligible infants in Ireland per HSE National Immunisation Office. Significantly reduces severe RSV in the first season. Check current HSE eligibility
• Maternal RSV vaccine — offered in pregnancy in some scenarios to protect newborns

Online Doctor consultation

For babies with cold symptoms but not unwell-looking, an Online Doctor can advise on monitoring and red flags. For any breathing concern, faster-than-usual breathing, reduced feeds, or significant illness — particularly in babies under 3 months — in-person assessment is the right pathway. Bronchiolitis is one condition where being cautious about in-person review is wise.