A common childhood upper-airway disorder, croup is among several respiratory illnesses that require pediatricians and other healthcare providers to make an accurate differential diagnosis to ensure appropriate treatment.
A common childhood upper-airway disorder, croup is among several respiratory illnesses that require pediatricians and other healthcare providers to make an accurate differential diagnosis to ensure appropriate treatment. It occurs most commonly in children aged between 6 months and 3 years and during the late autumn months, but sporadic cases can also occur any time of year and in older children.1,2
Although most cases of croup resolve on their own, children with even mild disease are now routinely treated with corticosteroids and those with more moderate to severe disease with immediate nebulized adrenaline.2,3 Very few children require hospitalization, with only about 1% to 8% of children needing hospitalization.2,3 Despite this, most children with symptoms of croup who present to the emergency department (ED) have only mild disease that does not require hospitalization.2,3
This article provides pediatricians and other pediatric healthcare providers with quick reference to the diagnosis and management of croup. The goal is to help pediatricians accurately diagnose and treat these children as well as educate their parents on the symptoms of the illness to help them know when to call their physician or when a visit to the ED is warranted.
Symptoms of croup can be similar to other respiratory diseases, so making the differential diagnosis is important to both treat appropriately and avoid unnecessary treatment. Most cases of croup are from a viral infection (called laryngotracheitis) or are spasmodic (called recurrent croup), although other conditions can mimic the symptoms of croup and need to be considered in making the differential diagnosis (Table 1).2
This article will focus on the diagnosis and treatment of croup, however pediatricians should be aware of recurrent croup and the potential for an underlying condition that may be masked by the persistence of croup symptoms (Table 2).4 For children with symptoms of recurrent croup, referral to an otolaryngologist is advised.
Croup related to a viral infection is most frequently caused by parainfluenza virus type 1 (and less commonly, type 3).2,5 Table 3 lists the different types of viruses that can cause croup.2, 6-8
Diagnosis is based primarily on history and physical examination. Most cases of viral croup are self-limiting and symptoms resolve on their own.3 Initial symptoms usually include an upper-respiratory-tract infection with low-grade fever and coryza. This is followed by a barking cough and mild to severe degrees of respiratory distress, including nasal flaring, stridor, and respiratory retractions.
The severity of respiratory distress is key to an accurate differential diagnosis as well as appropriate management, so assessment of the degree of airway obstruction is critical in the initial assessment.5,9 Assessment of the presence of stridor and the severity of retractions are the most reliable findings determining the severity of disease.2 Table 4 provides a list of key features to determine the severity of croup.3,4,9-10
For children who present with severe respiratory symptoms not from viral croup, other diagnostic imaging and lab work may be helpful along with the history and physical examination to make the differential diagnosis (Table 5).2 In determining the severity of croup as well as when treating croup, it is important to avoid upsetting the child or placing him or her under undue distress, because this can exacerbate symptoms of respiratory distress by further excessive narrowing of the airways.9,11
A single dose of a systemic corticosteroid is currently recommended as treatment of choice for croup, even in children with mild disease.3 Based on the current evidence, a single dose of oral dexamethasone (0.15 to 0.6 mg/kg of body weight) is the preferred choice of steroid based on its longer half-life.2
A single dose of nebulized budesonide (2 mg) is indicated based on the current best evidence for children with mild to moderate or moderate to severe croup who are vomiting or unable to take oral medications. Oral corticosteroids are preferred when tolerated, however, because they are more effective, convenient, and less expensive.3
Still unclear and needing further investigation is the optimal dose range of dexamethasone and whether repeated doses of corticosteroids provide additional benefit in children with severe croup.2,5 In addition, some evidence indicates a comparable efficacy between a single dose of dexamethasone and single oral dose of prednisolone (1 mg/kg) for mild to moderate croup, but more investigation is needed to evaluate the comparable efficacy given other data showing that patients with mild to moderate croup treated with prednisolone returned to the ED more frequently for more care.3
For children with moderate to severe croup, the addition of nebulized epinephrine is indicated by the current best evidence. Although the optimal dose of nebulized epinephrine in this setting is unknown, a dose of 3 ml of L-epinephrine, 1:1000 solution, has been recommended.3 Pediatricians need to keep in mind, however, that nebulized epinephrine has a short duration of action (less than 2 hours) and has no long-standing benefits.
Treatments that are not supported by the evidence, and therefore not recommended, include humidification therapy and Heliox.2,5
A number of algorithms have been proposed to facilitate treatment decisions based on the severity of croup. Figure 1 and Figure 2 provide examples of treatment algorithms based on recent systematic reviews of the literature.3,5
Most children with croup will not require hospitalization, but some children with severe croup or other symptoms of respiratory distress will need to be seen in the ED and/or admitted to the hospital. To date, good evidence is lacking on a standard to employ to admit a child to the hospital or to know when it is safe to discharge them from the ED.5 Table 6 provides some guidance.3
Croup is a common childhood upper-airway disorder most frequently caused by viral infection and occurring most often in children aged between 6 months and 3 years. Because symptoms can mimic symptoms of other disorders, a differential diagnosis considering the degree of airway obstruction is critical to ensure appropriate management. Standard treatment for all cases of croup regardless of severity is treatment with a single dose of a corticosteroid, with the addition of nebulized adrenaline for children with more moderate to severe disease.
Most children with croup will not need to be seen in the ED or need hospitalization. However, recognizing the signs and symptoms of more acute illness that does require hospitalization is important to reduce the number of unnecessary ED visits and hospitalizations.
1. Toward Optimized Practice Program. Guideline for the diagnosis and management of croup. Edmonton, Alberta: Alberta Medical Association. Available at: http://www.topalbertadoctors.org/download/252/croup_guideline.pdf. Revised January 2008. Accessed February 23, 2015.
2. Zoorob R, Sidani M, Murray J. Croup: an overview. Am Fam Physician. 2011;83(9):1067-1073.
3. Petrocheilou A, Tanou K, Kalampouka E, Malakasioti G, Giannios C, Kaditis AG. Viral croup: diagnosis and a treatment algorithm. Pediatr Pulmonol. 2014;49(5):421-429.
4. Joshi V, Malik V, Mirza O, Kumar BN. Fifteen-minute consultation: structured approach to management of a child with recurrent croup. Arch Dis Child Educ Pract Ed. 2014;99(3):90-93.
5. Bjornson CL, Johnson DW. Croup in children. CMAJ. 2013;185(15):1317-1323.
6. Cherry JD, Clinical practice. Croup. N Engl J Med. 2008;358(4):384-391.
7. Rihkanen H, Rönkkö E, Nieminen T, et al. Respiratory viruses in laryngeal croup of young children J Pediatr. 2008;152(5):661-665. Erratum in: J Pediatr. 2008;153(1):151.
8. Malhotra A, Krilov LR. Viral croup. Pediatr Rev. 2001;22(1):5-12. Erratum in: Pediatr Rev. 2001;22(9):292.
9. Rajapaksa S, Starr M. Croup-assessment and management. Aust Fam Physician. 2010;39(5):280-282.
10. Mazza D, Wilkinson F, Turner T, et al; Health for Kids Guideline Development Group. Evidence based guideline for the management of croup. Aust Fam Physician. 2008;37(6 spec no):14-20.
11. Everard ML. Acute bronchiolitis and croup. Pediatr Clin North Am. 2009;56(1):119-133.
Ms Nierengarten, a medical writer in St. Paul, Minnesota, has over 25 years of medical writing experience, coauthoring articles for Lancet Oncology, Lancet Neurology, Lancet Infectious Diseases, and Medscape. She has nothing to disclose in regard to affiliations with or financial interests in any organizations that may have an interest in any part of this article.