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This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.
Corticosteroids reduce symptoms of croup in children within two hours and continue to do so for at least 24 hours. They also cut the amount of time children spend in hospital by 15 hours and reduce return visits or readmissions from about 20% to 10%.
This Cochrane review assessed the effectiveness of corticosteroids such as dexamethasone and budesonide compared with placebo. It updates a previous review which concluded that corticosteroids reduce symptoms of croup at six hours.
The review also found that dexamethasone is more effective than budesonide at reducing croup symptoms at 6 and 12 hours - and lessens the need for adrenaline. However, rates of return visits and/or readmissions were similar, and there was no additional benefit from combining the two drugs.
The findings support recommendations that all children with mild, moderate, or severe croup should be treated immediately with corticosteroids.
Why was this study needed?
Croup, or laryngotracheobronchitis, is a common childhood respiratory condition, characterised by the sudden onset of a seal-like barking cough, often accompanied by high-pitched wheezing, a hoarse voice, and difficulty breathing. It affects around 3% of children per year - mostly between the ages of six months and three years - and is caused by swelling in the larynx and trachea triggered by a recent viral infection.
Although it has long been recognised that corticosteroids provide some clinical benefit for children with croup, many children don’t receive them, and there is continued medical debate in the timing of their use in this context.
The current review is an update of a Cochrane Systematic Review that was first published in 1999 and updated in 2004 and 2011. It incorporates five newly published studies and is the first time that risk of bias in the included studies, and the certainty of the evidence, have been assessed with the respective Cochrane tools.
What did this study do?
The review compared the effectiveness of corticosteroids to placebo for treating croup in children. It assessed whether they reduced croup symptoms, minimised return visits or shortened length of hospital stay, reduced the need for additional treatments, or had side effects.
The 43 studies (including five new to this update) covered 4,565 children. The corticosteroids investigated included beclomethasone, betamethasone, budesonide, dexamethasone, fluticasone, and prednisolone. Most studies compared corticosteroids to placebo, although some compared them to adrenaline, to another corticosteroid, or combination of corticosteroids; or compared corticosteroids given in different ways, or amounts.
The studies took place in North America, Europe, Asia and Australia.
Few studies had a low overall risk of bias, and many biases were unclear from the reporting. However, using the GRADE system the certainty of evidence was thought to be moderate meaning that readers can be moderately confident in the effect estimate.
What did it find?
- Compared with placebo, corticosteroids improved symptoms of croup at two hours (standardised mean difference [SMD] ‐0.65, 95% confidence interval [CI] ‐1.13 to ‐0.18; 7 trials, 426 children), and the effect lasted for at least 24 hours (SMD ‐0.86, 95% CI ‐1.40 to ‐0.31; 8 trials, 351 children).
- The rates of return visits or (re)admissions or both were halved by corticosteroids (risk ratio 0.52, 95% CI 0.36 to 0.75). When given corticosteroids, 106 of every 1,000 children treated will return for medical care, compared with 204 of every 1,000 children treated with placebo.
- Corticosteroids reduced children’s length of hospital stay by 15 hours (range 6 to 24 hours) compared with placebo, but made no difference to their need for additional treatments.
- Few serious adverse events were associated with short‐term corticosteroid treatment for croup.
What does current guidance say on this issue?
The NICE Clinical Knowledge Summary on croup (updated in 2017) recommends that all children with mild, moderate, or severe croup should receive a single dose of oral dexamethasone (0.15 mg per kg body weight). If the child is too unwell to receive medication, inhaled budesonide (2 mg nebulised as a single dose) or intramuscular dexamethasone (0.6 mg/kg as a single dose) are alternatives.
What are the implications?
The findings of this large, high quality review reinforce current recommendations and practice with a moderate degree of certainty. They suggest that corticosteroids rapidly reduce symptoms of croup in children, within about 2 hours and that the effect lasts for at least 24 hours.
The findings may support earlier escalation of therapy (following a lack of response at 2 hours).
Shorter hospital stays and the reduction in readmission rates from about 20% to 10% are important outcomes for health systems and commissioners of child services.
Citation and Funding
Gates A, Gates M, Vandermeer B et al. Glucocorticoids for croup in children. Cochrane Database Syst Rev. 2018;8;CD001955.
This project was funded by the Alberta Research Centre for Health Evidence at the University of Alberta, Canada
Bibliography
NHS website. Croup. London: Department of Health and Social Care; updated 2017.
NICE. Croup. Clinical Knowledge Summary. London: National Institute for Health and Care Excellence; 2017.
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