Westley Croup Score Calculator

How to Use This Calculator

1. Select the score for each of the 5 Westley criteria from clinical assessment.
2. Total score (0-17), severity category, and treatment guidance display instantly.
3. Treatment tab calculates dexamethasone dose by weight.
4. DDx tab lists dangerous mimics to exclude.

Formula

Example

Frequently Asked Questions

• What is the Westley Croup Score and what does it measure? ▼
  The Westley Croup Score is the most widely validated and used clinical scoring system for assessing the severity of croup (laryngotracheobronchitis) in children. Developed by Westley, Cotton, and Brooks and published in the American Journal of Diseases of Children in 1978, it evaluates five clinical parameters: inspiratory stridor (0-2 points), chest wall retractions (0-3 points), air entry on auscultation (0-2 points), cyanosis (0-5 points), and level of consciousness (0-5 points). Total score ranges from 0 to 17. Severity is categorized as mild (0-2), moderate (3-7), severe (8-11), and impending respiratory failure (12-17). Croup is a viral upper airway infection — most commonly caused by parainfluenza virus types 1, 2, and 3 — that causes subglottic edema and the characteristic barking cough, inspiratory stridor, and hoarse voice. It predominantly affects children 6 months to 3 years of age. The Westley Score standardizes clinical assessment across practitioners and settings, enabling consistent treatment decisions — particularly regarding when to add nebulised epinephrine to corticosteroid therapy and when hospital admission is required. It has been used as the primary outcome measure in landmark randomized controlled trials of dexamethasone and epinephrine for croup.
• How is dexamethasone used in croup and what dose is recommended? ▼
  Dexamethasone is the cornerstone of croup treatment and has strong evidence from multiple randomized controlled trials and Cochrane reviews demonstrating significant reduction in Westley scores, shorter ED stays, lower return visits, and reduced hospitalization rates. The recommended dose is 0.6 mg/kg orally or intramuscularly, with a maximum dose of 10 mg. A single dose is sufficient in the vast majority of cases. Lower doses (0.15 mg/kg) have been studied and found to be almost equally effective in mild-to-moderate croup, though 0.6 mg/kg remains the standard recommendation in most guidelines. Oral and IM routes are equally effective; oral is preferred when the child can tolerate it, as it avoids the distress of an injection. Budesonide 2 mg nebulised is an alternative when oral or IM dexamethasone is not feasible. Dexamethasone should be given to all children with croup presenting to the ED or clinical care settings — even mild croup — because it reduces symptom duration and return visits. The anti-inflammatory mechanism involves reducing subglottic mucosal edema through glucocorticoid receptor-mediated suppression of inflammatory cytokines and airway edema formation. The clinical effect begins within 1-3 hours and persists for 12-24 hours. No pretreatment observation period before discharge is necessary after dexamethasone in mild cases.
• When is nebulised epinephrine used in croup and how is it given? ▼
  Nebulised epinephrine is indicated for moderate-to-severe croup (Westley score ≥3-4 or significant inspiratory stridor at rest with increased work of breathing) and provides rapid symptomatic relief through alpha-adrenergic-mediated vasoconstriction of subglottic mucosal blood vessels, reducing edema within 10-30 minutes. The effect is transient, lasting approximately 1-3 hours, after which symptoms may return to their pre-treatment level — a phenomenon called rebound — so patients must be observed for a minimum of 2-4 hours after the last epinephrine dose before discharge. Two formulations are used: racemic epinephrine 0.5 mL of 2.25% solution in 3 mL normal saline, and L-epinephrine (standard 1:1000 adrenaline) at 0.5 mL/kg (maximum 5 mL) in 3 mL normal saline via nebuliser or face mask. Evidence comparing racemic and L-epinephrine demonstrates equivalent efficacy, and L-epinephrine is now preferred at most centers as it is universally available and cost-effective. A child who has received epinephrine and is stable and improving 3-4 hours post-dose may be discharged home provided they have also received dexamethasone and parents are reliable for return if symptoms recur. Repeated epinephrine doses are safe and should be given as needed in severe cases. Heliox (helium-oxygen) is occasionally used in refractory severe croup.
• What features distinguish croup from its dangerous mimics? ▼
  While viral croup (laryngotracheobronchitis) is by far the most common cause of stridor and barking cough in young children, several dangerous conditions can present similarly and must not be missed. Epiglottitis, caused by Haemophilus influenzae type b (now rare after vaccination) or Streptococcus pyogenes, presents with rapid onset, high fever, toxic appearance, drooling, throat pain, and the classic tripod or sniffing position. The child avoids the supine position and looks ill. Unlike viral croup, there is typically no barking cough and no preceding upper respiratory illness. Suspected epiglottitis is a true emergency — do not attempt to examine the throat or agitate the child; call anesthesia and ENT immediately for controlled airway management in the operating theater. Bacterial tracheitis (pseudomembranous croup) is caused by Staphylococcus aureus and presents with initial croup-like illness that rapidly progresses to high fever, toxicity, and severe airway obstruction unresponsive to nebulised epinephrine — the key differentiator. Foreign body aspiration should be considered in any child with sudden onset stridor, especially without prodromal viral illness. Retropharyngeal or peritonsillar abscess presents with muffled voice, dysphagia, and neck extension stiffness. Anaphylaxis can mimic croup with acute stridor but is accompanied by urticaria, hypotension, and exposure history. The Westley score is specific to viral croup and should not be applied to these dangerous alternatives.
• When should a child with croup be admitted to hospital? ▼
  Admission criteria for croup are guided primarily by the Westley score and clinical response to initial treatment in the emergency department. Children with mild croup (Westley 0-2) who respond to dexamethasone and have no persisting respiratory distress may be discharged with clear return precautions. Children with moderate croup (Westley 3-7) should receive dexamethasone and be observed for 2-4 hours; if they improve to mild croup category and remain stable, discharge is appropriate. Those who do not improve or worsen despite treatment should be admitted. Children with severe croup (Westley 8-11) generally require admission for monitoring, supplemental oxygen, repeated epinephrine doses, and parenteral steroids. Indications for PICU admission include Westley score ≥12 (impending failure), persistent stridor at rest after multiple epinephrine doses, hypoxia requiring supplemental oxygen above 40% FiO2, altered level of consciousness, young age under 6 months (higher risk of respiratory fatigue), suspected bacterial tracheitis or epiglottitis, or unreliable social circumstances. The 2021 NICE guideline recommends observation in ED after nebulised epinephrine for a minimum of 2 hours. Humidified air/mist therapy — once widely used — has been shown in multiple RCTs to provide no measurable benefit over standard room air for croup and is no longer recommended.

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