Croup / Laryngotracheobronchitis

A toddler wakes at 2 AM with a harsh, seal-like bark and audible stridor — the hallmark presentation that separates croup from its more dangerous mimic, epiglottitis.

Croup (laryngotracheobronchitis) is a viral upper airway infection most commonly caused by parainfluenza virus, affecting children ages 6 months to 3 years, with peak incidence around age 2. The inflammation narrows the subglottic airway, producing the classic triad: barking (seal-like) cough, inspiratory stridor, and hoarseness. Symptoms characteristically worsen at night and often follow 1–2 days of URI symptoms such as low-grade fever and rhinorrhea. An anteroposterior neck X-ray shows the steeple sign — subglottic narrowing that tapers like a church steeple. Mild croup is managed with comfort measures and cool mist exposure, though current evidence does not support its efficacy. Moderate-to-severe croup requires nebulized racemic epinephrine for rapid but temporary airway relief (effects wear off in about 2 hours, so the child must be observed for rebound stridor) and a single dose of oral or IM dexamethasone (0.6 mg/kg, max 10 mg), which reduces airway edema within 2–6 hours and lasts up to 72 hours. Agitation worsens airway obstruction, so keeping the child calm — often in a parent's lap — is a genuine nursing intervention, not just comfort care.

Key Distinctions

Don't confuse croup with epiglottitis: croup has gradual onset, barking cough, low-grade fever, and a steeple sign; epiglottitis presents with abrupt high fever, drooling, tripod positioning, a muffled voice, and a thumbprint sign. Students often think cool mist treats the inflammation — it only soothes irritated mucosa and lacks strong evidence of benefit. Remember that racemic epinephrine provides temporary relief; discharge before a 2-hour observation period risks rebound obstruction.

Clinical Pearl

Steeple = croup (subglottic). Thumbprint = epiglottitis (supraglottic). If the child is barking like a seal at 2 AM, think croup first.