What is the step‑wise treatment algorithm for viral croup in a 17‑month‑old child with a bark‑like cough, including severity assessment and management for mild, moderate, and severe disease?

Treatment Algorithm for Viral Croup in a 17-Month-Old Child

Every child with suspected viral croup should receive a single oral dose of dexamethasone 0.15-0.60 mg/kg (maximum 10 mg) immediately, regardless of severity, and nebulized epinephrine should be added only for moderate-to-severe cases with stridor at rest or respiratory distress. 1, 2, 3

Initial Assessment and Diagnosis

Clinical Features to Assess:

• Barking ("seal-like") cough is the hallmark symptom 1
• Inspiratory stridor (present at rest indicates moderate-to-severe disease) 4, 3
• Use of accessory muscles, tracheal tug, chest wall recession 1
• Respiratory rate (>70 breaths/min in infants is concerning) 5
• Oxygen saturation (<92% requires admission) 5, 1
• Ability to speak/cry normally 1
• Level of agitation (may signal hypoxemia, not anxiety) 1

Differential Diagnoses to Exclude:

• Bacterial tracheitis 1
• Foreign body aspiration 1
• Epiglottitis 1
• Retropharyngeal or peritonsillar abscess 1

Imaging is NOT needed for typical croup presentations; diagnosis is clinical 1, 4

Severity Classification and Treatment Algorithm

Mild Croup (Stridor only with agitation, no respiratory distress)

1. Administer oral dexamethasone 0.15-0.60 mg/kg (maximum 10 mg) as a single dose 1, 2, 3

   • If oral route not tolerated, use intramuscular dexamethasone 0.6 mg/kg 4, 6
   • Alternative: nebulized budesonide 2 mg if dexamethasone unavailable 2, 3

2. Supportive care:

   • Maintain oxygen saturation ≥94% with supplemental oxygen if needed 1
   • Minimize handling to reduce metabolic demand 1
   • Use antipyretics for comfort 1
   • Ensure adequate hydration 1

3. Observation:

   • Monitor for 2-4 hours if symptoms improve 1
   • Discharge if no respiratory distress and reliable caregiver present 1

Moderate-to-Severe Croup (Stridor at rest, respiratory distress, accessory muscle use)

1. Immediate dual therapy:

   • Oral dexamethasone 0.6 mg/kg (maximum 10 mg) 1, 4, 2
   • PLUS nebulized epinephrine 0.5 mL/kg of 1:1000 solution (racemic epinephrine) 1, 4, 2

2. Oxygen therapy:

   • Administer via nasal cannula, head box, or face mask to maintain SpO₂ ≥94% 1

3. Critical monitoring after epinephrine:

   • Observe for minimum 2 hours after EACH dose due to short-lived effect (1-2 hours) and risk of rebound symptoms 1, 4, 2
   • Never discharge within 2 hours of epinephrine administration 1
   • Monitor oxygen saturation at least every 4 hours 1

4. Repeat epinephrine dosing:

   • May repeat nebulized epinephrine if symptoms recur 4, 2
   • Restart 2-hour observation clock after each dose 1

Hospitalization Criteria

Admit to hospital if ANY of the following:

• Three or more doses of nebulized epinephrine required 1
• Age <18 months with severe symptoms 1
• Oxygen saturation <92% on room air 5, 1
• Respiratory rate >70 breaths/min 5
• Inability of family to provide appropriate observation 1
• Life-threatening signs: silent chest, cyanosis, fatigue/exhaustion, poor respiratory effort 1

Recent evidence shows that limiting admission until 3 doses of epinephrine are needed reduces hospitalization rates by 37% without increasing revisits or readmissions. 1

Discharge Criteria

All of the following must be met:

• At least 2 hours elapsed since last nebulized epinephrine with no rebound symptoms 1
• Oxygen saturation >92% on room air 1
• No signs of respiratory distress 1
• Respiratory rate <50 breaths/min 1
• Reliable caregiver able to monitor and return if needed 1

Follow-Up Instructions

• Return immediately if respiratory distress worsens, stridor increases, or child cannot maintain hydration 1
• Follow up with primary care if symptoms not improved within 48 hours 1
• Continue antipyretics for fever control 1
• Maintain adequate fluid intake 1

Critical Pitfalls to Avoid

Medications to AVOID:

• Do NOT use over-the-counter cough or cold medications (no benefit, potential harm) 5, 1
• Do NOT use antihistamines or decongestants (ineffective and potentially harmful) 5, 1
• Do NOT use honey (only helpful for post-viral cough, not acute croup) 1
• Do NOT use chest physiotherapy (no benefit, may cause harm) 1

Clinical Errors:

• Never discharge within 2 hours of epinephrine due to rebound risk 1, 4
• Never use nebulized epinephrine in outpatient settings where immediate return is not feasible 1
• Do NOT perform blind finger sweeps if foreign body suspected (may push object deeper) 1
• Do NOT rely on lateral neck radiographs for diagnosis (clinical assessment superior) 1

Positioning for age 17 months:

• Use neutral head position with roll under shoulders to optimize airway patency 1

Special Considerations for Persistent or Recurrent Croup

If cough persists ≥4 weeks:

• Obtain chest radiograph 5, 1
• Perform spirometry if child ≥6 years old 7
• Consider underlying airway abnormalities (tracheomalacia, laryngomalacia) 5, 1
• Consider flexible bronchoscopy if severe, persistent, or atypical presentation (68% have lower airway abnormalities) 1

Recurrent croup episodes warrant:

• Evaluation for asthma (especially if nocturnal worsening, exercise triggers, family history of atopy) 1
• Assessment for gastroesophageal reflux 1
• Consider prophylactic inhaled corticosteroids if asthma features present 1