Croup: Diagnosis and Management PDF

Croup: Diagnosis and Management Dustin K. Smith, DO; Andrew J. McDermott, MD; and John F. Sullivan, DO Naval Hospital Jacksonville, Jacksonville, Florida Croup is a common respiratory illness affecting...

Croup: Diagnosis and Management Dustin K. Smith, DO; Andrew J. McDermott, MD; and John F. Sullivan, DO Naval Hospital Jacksonville, Jacksonville, Florida Croup is a common respiratory illness affecting 3% of children six months to three years of age. It accounts for 7% of hospitalizations annually for fever and/or acute respiratory illness in children younger than five years. Croup is a mani- festation of upper airway obstruction resulting from swelling of the larynx, trachea, and bronchi, leading to inspiratory stridor and a barking cough. Many patients experience low-grade fevers, but fever is not necessary for diagnosis. Less commonly, stridor can be associated with acute epiglottitis, bacterial tracheitis, and foreign body airway obstruction. Laboratory studies are seldom needed for diagnosis of croup. Viral cultures and rapid antigen testing have minimal impact on management and are not routinely recommended. Radiography and laryngoscopy should be reserved for patients in whom alternative diagnoses are suspected. Randomized controlled trials have demonstrated that a single Illustration by Jonathan Dimes dose of oral, intramuscular, or intravenous dexamethasone improves symptoms and reduces return visits and length of hospitalization in children with croup of any severity. In patients with moderate to severe croup, the addition of neb- ulized epinephrine improves symptoms and reduces length of hospitalization. (Am Fam Physician. 2018;97(9):575-580. Copyright © 2018 American Academy of Family Physicians.) Croup is a common respiratory illness of the in boys than in girls (1.5:1 ratio). Although the larynx, trachea, and bronchi that leads to inspi- incidence of croup is highest between six months ratory stridor and a barking cough. Laryngotra- and three years of age, it can occur in children up cheitis, laryngotracheobronchitis, and laryngo- to six years of age, or earlier than six months in tracheobronchopneumonitis are included in the atypical cases.5-7 Approximately 85% of cases are croup spectrum and affect 3% of children six defined as mild, and less than 1% meet criteria months to three years of age.1,2 Each year in the for severe croup, which can be distinguished by United States, croup accounts for 7% of hospital- signs of hypoxia.8,9 Less than 5% of all children izations for fever and/or acute respiratory illness with croup are hospitalized, and of those only 1% in children younger than five years.3,4 to 3% require intubation.10 In patients with recurrent croup (more than two Epidemiology episodes per year), clinically significant bronchos- Croup is typically self-limited in immuno- copy findings are associated with risk factors such competent children, occurring predominantly as prior intubation, prematurity, and age younger during the fall and winter. It is more common than three years. Although gastroesophageal reflux disease and asthma are highly prevalent in patients with recurrent croup, neither is associated Patient information: A handout on this topic, written by the with significant bronchoscopy findings.11 authors of this article, is available at https://www.aafp.org/ afp/2018/0501/p575-s1.html. Outcomes are favorable; croup has a mortality CME This clinical content conforms to AAFP criteria for rate of less than 0.5%, even for intubated patients.10 continuing medical education (CME). See CME Quiz on page 565. Etiology Author disclosure: No relevant financial affiliations. Viruses are detected in up to 80% of patients who have croup with identifiable pathogens.12 Downloaded May 1, 2018from the American ◆ Volume Family Physician 97, Number 9 website at www.aafp.org/afp. Copyright © 2018 American Academy of Family www.aafp.org/afp Physicians. American For the Family 575 private, noncom- Physician mercial use of one individual user of the website. All other rights reserved. Contact [email protected] for copyright questions and/or permission requests.  CROUP cough, inspiratory stridor, SORT: KEY RECOMMENDATIONS FOR PRACTICE and hoarseness (https:// w w w.yout u b e.c om / Evidence watch?v=R XJx t AHt kcs). Clinical recommendation rating References Many patients will also Diagnosis of croup is based on clinical findings of C 5, 6 have dyspnea and fever, 5,6 barking cough, stridor, and hoarseness. Diagnostic but the absence of fever testing is typically not necessary. should not reduce suspi- Humidified air inhalation does not improve symptoms B 27 cion for croup. in patients with moderate croup. Respiratory rate is often increased in patients with Corticosteroids should be administered to patients A 21, 22 croup. Clinicians should with croup of any severity. use age-appropriate rates; Epinephrine should be administered to patients with A 25, 26 for patients six months to moderate to severe croup. three years of age, a nor- A = consistent, good-quality patient-oriented evidence; B = inconsistent or mal rate is 20 to 30 breaths limited-quality patient-oriented evidence; C = consensus, disease-oriented evi- per minute. Additionally, dence, usual practice, expert opinion, or case series. For information about the patients can present with SORT evidence rating system, go to http://www.aafp.org/afpsort. tachycardia. If pulse oxim- etry is performed, low oxy- gen levels may be noted in carp is Parainfluenza virus (types 1 to 3) accounts for patients with more severe cases.12-15 75% of all cases, and human parainfluenza virus 1 Visual inspection can reveal clues to the sever- by is the most common type.9,13 Other viral etiologies ity of illness. Retractions and nasal flaring may caused& include influenza A and B, adenovirus, respira- indicate more severe cases. Although cyanosis is beia mal tory syncytial virus, rhinovirus, and enterovirus. absent in most patients with croup, its presence Viral infection of the subglottic region and laryn- suggests severe disease.12,13,16 etiolog geal mucosa causes inflammation and edema, - The most common auscultatory finding is which significantly decrease air movement and overt inspiratory stridor in the neck. If wheez- lead to respiratory distress and stridor.9,13 Bacte- ing is present, it is typically mild; substantial rial croup is less common and may be caused by wheezing should prompt evaluation for alter- Mycoplasma pneumoniae and Corynebacterium nate diagnoses. Rhonchi may be present but diphtheriae.8,12 The type of infectious agent does are not typical. Rales are generally not present not affect outcomes or initial management. in croup, so this finding should prompt further evaluation.12,13,16 Presentation and Clinical Course Viral croup often presents similarly to an upper WHAT IS NEW ON THIS TOPIC respiratory infection, with 12 to 72 hours of low- grade fever and coryza. Narrowing of the larynx leads to stridor, increased respiratory rate, respira- Croup tory retractions, and a barking cough. Symptoms A community-based randomized trial of children with may be exacerbated by emotional distress, are mild to moderate croup found no difference in symptom scores between a single dose of dexamethasone and worse at night, and peak between 24 and 48 hours. three daily doses of prednisolone. Croup typically resolves spontaneously within 48 hours to one week; however, the abrupt onset In patients with more than two croup episodes per year, and harsh cough can be concerning.5,6 clinically significant bronchoscopy findings are associated with risk factors such as prior intubation, age younger than three years, and prematurity. Although gastroesoph- Diagnosis ageal reflux disease and asthma are highly prevalent in HISTORY AND PHYSICAL EXAMINATION patients with recurrent croup, neither is associated with Croup is primarily a clinical diagnosis, with significant bronchoscopy findings. typical findings of abrupt onset of a barking 576 American Family Physician www.aafp.org/afp Volume 97, Number 9 ◆ May 1, 2018  CROUP DIFFERENTIAL DIAGNOSIS croup from epiglottitis, whereas drooling is More than 99% of children with abrupt stri- highly sensitive and specific for distinguishing dor have croup, but the differential diagnosis is epiglottitis.20 broad6 (Table 1 2,5,6,14,16-18). Differentiating croup from other acute illnesses can be challenging. DIAGNOSTIC TESTING Specifically, distinguishing it from epiglottitis is Laboratory studies are seldom needed to diag- important because the treatment and prognosis nose croup. Viral cultures and rapid antigen of these conditions are substantially different.7 testing should be reserved for patients in whom Although both conditions commonly present as initial treatment is ineffective.6 A complete cough, fever, and dyspnea, epiglottitis is 10 times blood count may help distinguish croup from more likely to present as sore throat.7 The inci- bacterial etiologies of stridor (e.g., bacterial dence of epiglottitis has decreased 10-fold with tracheitis, epiglottitis, peritonsillar abscess, widespread Haemophilus influenzae type B vac- retropharyngeal abscess), but it is nonspecific. cination, but it is still important to distinguish Lymphocytosis may suggest a viral etiology.5,6 it from croup because of potentially rapid deteri- A carboxyhemoglobin level may be helpful in oration in patients with epiglottitis.19 In patients identifying cases of thermal injury/smoke inha- admitted to the intensive care unit, cough is lation, but the history alone is typically sufficient highly sensitive and specific for distinguishing for this diagnosis. TABLE 1 Differential Diagnosis of Croup and Associated Clinical Features Condition Typical age range Presentation Diagnostic tests Bacterial tracheitis < 6 years High fever, barking cough, respira- Neck radiography (irregular tracheal tory distress, and rapid deterioration mucosa) and CBC Croup 6 months to 3 years Acute onset of barking cough, stri- None required dor, and hoarseness Epiglottitis 3 to 12 years Acute onset of dysphagia, odyno- Neck radiography (thickened epiglot- phagia, drooling, high fever, anxiety, tis) and CBC and muffled voice Foreign body < 3 years Acute onset of choking and/or Neck radiography, neck CT, and aspiration drooling airway endoscopy Hemangioma < 6 months Stridor worse with crying Airway endoscopy Large airway < 6 months to 4.5 years Recurrent episodes of barking cough Airway endoscopy lesions* and stridor Neoplasm No age predilection Progressive airway symptoms Lateral neck radiography and CT Peritonsillar 6 months to 3.5 years Sore throat, fever, “hot potato” voice Neck radiography, neck CT, and CBC abscess Retropharyngeal 2 to 4 years Fever, drooling, dysphagia, odyno- Neck radiography (bulging posterior abscess phagia, and neck pain pharyngeal wall), neck CT, and CBC Thermal injury/ No age predilection Exposure to heat, smoke, or Direct laryngoscopy smoke inhalation chemical CBC = complete blood count; CT = computed tomography. *—Large airway lesions include subglottic stenosis, laryngeal cleft, tracheomalacia, and laryngomalacia. Information from references 2, 5, 6, 14, and 16 through 18. May 1, 2018 ◆ Volume 97, Number 9 www.aafp.org/afp American Family Physician 577  TABLE 2 Westley Croup Score Clinical sign Score Although radiographic imaging is not rou- Level of consciousness tinely indicated, croup is often associated with Normal (including sleep) 0 the steeple sign, which indicates glottic and Disoriented 5 subglottic narrowing (see http://www.aafp.org/ afp/2004/0201/p535.html#afp20040201p535-f1). Cyanosis However, this finding is neither specific nor sen- None 0 sitive for croup and may be present in patients With agitation 4 with epiglottitis, bacterial tracheitis, neoplasm, At rest 5 or thermal injury.18 Computed tomography of the Stridor neck can be considered for patients with suspected None 0 abscess, tumor, or foreign body aspiration.5 When agitated 1 Laryngoscopy should be reserved for atypical presentations or when alternate diagnoses are At rest 2 suspected.16 If epiglottitis is suspected, laryngos- Air entry copy should be performed with caution because Normal 0 of concern for rapid airway obstruction.6 Decreased 1 Markedly decreased 2 Management Management of croup is based on the severity of Retractions illness. Although a scoring system is not neces- None 0 sary, the most widely studied and commonly used Mild 1 is the Westley Croup Score (Table 2).15 Figure 1 Moderate 2 provides an outpatient management algorithm Severe 3 for children with croup.6,14,21-26 Minimizing agi- Total score Croup severity tation in a symptomatic child can help improve ≤2 Mild symptoms. Placing the child in a comfortable position may help improve the evaluation and 3 to 7 Moderate treatment process. 8 to 11 Severe Oxygen should be administered to children ≥ 12 Impending respiratory failure with hypoxemia or severe respiratory distress. Although humidified air inhalation has been Adapted with permission from Westley CR, Cotton EK, Brooks JG. historically used for management of croup, a Nebulized racemic epinephrine by IPPB for the treatment of croup: a double-blind study. Am J Dis Child. 1978;132(5):485. meta-analysis of three studies (N = 125) found no statistically significant effect on croup scores or hospital admission in patients with moderate croup.27 Treatment with specifically designed and decreased return to medical care.21 Corti- humidity droplets that deposit in the larynx is no costeroids are thought to work by decreasing better than controlled delivery of 40% humidity laryngeal mucosal edema through their anti- or humidity via blow-by administration.28 inflammatory effects. A Cochrane review showed Heliox is a helium and oxygen mixture used improved symptom scores at six and 12 hours for respiratory conditions that theoretically after treatment with a corticosteroid (dexameth- improves airflow resistance by decreasing gas asone, budesonide [Rhinocort], or methylpred- density (helium is a low-density gas). Data are nisolone).22 Patients treated with corticosteroids limited on the benefit of heliox in the treatment have a lower rate of return visits, as well as of croup, and based on a Cochrane review of decreased length of stay in the emergency depart- three conflicting trials, it is not recommended.29 ment or hospital. There is no statistically signif- icant difference between corticosteroids and CORTICOSTEROIDS epinephrine, although patients treated with cor- Corticosteroids should be used in patients with ticosteroids require less epinephrine.22 Another croup of any severity. Treatment with dexameth- review showed that corticosteroids are safe to use asone results in faster resolution of symptoms in children with acute respiratory conditions.23 578 American Family Physician www.aafp.org/afp Volume 97, Number 9 ◆ May 1, 2018  FIGURE 1 Clinical assessment of croup severity dexamethasone and three daily doses of prednisolone for treatment of mild Mild: occasional barking cough Moderate or severe: frequent to moderate croup.24 without audible stridor at rest barking cough with marked stridor (Westley Croup Score ≤ 2) and visible respiratory retractions at rest (Westley Croup Score ≥3) EPINEPHRINE Epinephrine is thought to improve Administer dexamethasone (0.15 to 0.60 mg per kg orally Administer dexamethasone symptoms in patients with croup or parenterally, single dose) (0.15 to 0.60 mg per kg orally or through arteriole vasoconstriction parenterally, single dose) in the upper airway mucosa, which eventually leads to decreased edema. Counsel parents about illness and when to seek Administer nebulized epinephrine Epinephrine is typically used in con- medical attention (up to 0.5 mL of racemic epinephrine junction with corticosteroids because 2.25% or up to 5 mL of L-epinephrine it has a quick onset of action but a short 1:1,000); repeat as needed half-life, whereas corticosteroids have Consider sending child home if he or she is a slower onset of action but a longer stable with no stridor Provide oxygen if indicated half-life. Epinephrine decreases symp- tom scores in children with moderate or severe croup and should be given Observe for up to 4 hours at the recommended dose of 0.05 mL per kg of racemic epinephrine 2.25% (maximum dose = 0.5 mL) or 0.5 mL per kg of L-epinephrine 1:1,000 via Symptoms improve Symptoms do not improve nebulizer (maximum dose = 5 mL).25,26 A Cochrane review showed that neb- Counsel parents about ulized epinephrine reduces symptom illness and when to Consider scores at 30 minutes, but not at two seek medical attention hospitalization and six hours; however, it is associated with reduced length of hospitaliza- Consider sending child tion.25 There was no initial difference home if he or she is between nebulized racemic epineph- stable with no stridor rine and L-epinephrine, although L-epinephrine was more effective at Algorithm for the management of croup. two hours because of its longer effects. Adapted with permission from Zoorob R, Sidani M, Murray J. Croup: an overview. The effects of epinephrine wane after Am Fam Physician. 2011;83(9):1071, with additional information from references one to two hours, so patients should be 6, and 21 through 26. monitored for at least two hours after administration before they are dis- charged.6,25 Although adverse effects of Dexamethasone is the preferred corticosteroid nebulized epinephrine are rare, patients receiv- because it is given as a single dose and can be ing frequent treatments should be monitored for given orally, intramuscularly, or intravenously. adverse cardiac effects. Although the optimal dose is unclear, 0.6 mg This article updates previous articles on this topic by per kg is the most commonly used.13,24 Dexa- Zoorob, et al.,14 and by Knutson and Aring.17 methasone is superior to budesonide for improv- Data Sources: A PubMed search was completed ing symptoms scores, but there is no significant using the key terms croup and pediatric respiratory difference in return visits or readmissions. Com- infection. The search included meta-analyses, ran- pared with prednisolone, dexamethasone use domized controlled trials, clinical trials, and reviews. in the emergency department or hospital may We also searched the Cochrane database, Essential Evidence Plus, and the National Guideline Clear- decrease rates of return visits or readmissions.22 inghouse. In addition, references in these resources However, a community-based randomized were searched. Search dates: November 7, 2016; July trial found no difference between single-dose 19, 2017; and December 27, 2017. May 1, 2018 ◆ Volume 97, Number 9 www.aafp.org/afp American Family Physician 579  CROUP The views expressed in this article are those of the bronchitis): biennial increases associated with human authors and do not necessarily reflect the official parainfluenza virus 1 epidemics. J Infect Dis. 1997;176(6): policy or position of the Department of the Navy, 1423-1427. Department of Defense, or the U.S. government. 10. Kwong K, Hoa M, Coticchia JM. Recurrent croup presen- tation, diagnosis, and management. Am J Otolaryngol. We are military service members. This work was 2007;28(6):401-407. prepared as part of our official duties. Title 17 U.S.C. 11. Hiebert JC, Zhao YD, Willis EB. Bronchoscopy findings in 105 provides that “Copyright protection under this recurrent croup: a systematic review and meta-analysis. title is not available for any work of the United States Int J Pediatr Otorhinolaryngol. 2016;90:86-90. Government.” Title 17 U.S.C. 101 defines United States 12. Cherry JD. Clinical practice. Croup. N Engl J Med. 2008; Government work as a work prepared by a military 358(4):384-391. service member or employee of the United States 13. Johnson DW. Croup. BMJ Clin Evid. 2014;2014. Government as part of that person’s official duties. 14. Zoorob R, Sidani M, Murray J. Croup: an overview. Am Fam Physician. 2011;83(9):1067-1073. The Authors 15. Westley CR, Cotton EK, Brooks JG. Nebulized racemic epinephrine by IPPB for the treatment of croup: a double- DUSTIN K. SMITH, DO, is an assistant program blind study. Am J Dis Child. 1978;132(5):484-487. director at the Jacksonville Family Medicine Resi- 16. Cooper T, Kuruvilla G, Persad R, El-Hakim H. Atypical dency Program, Naval Hospital Jacksonville (Fla.). croup: association with airway lesions, atopy, and esopha- gitis. Otolaryngol Head Neck Surg. 2012;147(2):209-214. ANDREW J. MCDERMOTT, MD, is a faculty mem- 17. Knutson D, Aring A. Viral croup. Am Fam Physician. 2004; ber at the Jacksonville Family Medicine Residency 69(3):535-540. Program, Naval Hospital Jacksonville. 18. Huang CT. Steeple sign: not specific for croup. J Emerg Med. 2012;43(5):e333-e334. JOHN F. SULLIVAN, DO, is a second-year resident 19. Faden H. The dramatic change in the epidemiology of at the Jacksonville Family Medicine Residency pediatric epiglottitis. Pediatr Emerg Care. 2006;22(6): Program, Naval Hospital Jacksonville. 443-444. 20. Tibballs J, Watson T. Symptoms and signs differentiating Address correspondence to Dustin K. Smith, DO, croup and epiglottitis. J Paediatr Child Health. 2011;47(3): Naval Hospital Jacksonville, 2080 Child St., Jack- 77-82. sonville, FL 32214 (e-mail: dustin.k.smith16.mil@ 21. Bjornson CL, Klassen TP, Williamson J, et al.; Pediatric mail.mil). Reprints are not available from the Emergency Research Canada Network. A randomized trial authors. of a single dose of oral dexamethasone for mild croup. N Engl J Med. 2004;351(13):1306-1313. 22. Russell KF, Liang Y, O’Gorman K, Johnson DW, Klassen TP. References Glucocorticoids for croup. Cochrane Database Syst Rev. 1. Cherry JD. Croup (laryngitis, laryngotracheitis, spas- 2011;(1):CD001955. modic croup, and laryngotracheobronchitis). In: Cherry 23. Fernandes RM, Oleszczuk M, Woods CR, Rowe BH, Cates JD, Demmler-Harrison GJ, Kaplan SL, et al., eds. Feigin & CJ, Hartling L. The Cochrane Library and safety of sys- Cherry’s Textbook of Pediatric Infectious Diseases. 7th ed., temic corticosteroids for acute respiratory conditions in vol. 1.Philadelphia, Pa.: Elsevier Saunders; 2014:241-260. children: an overview of reviews. Evid Based Child Health. 2. Kaditis AG, Wald ER. Viral croup: current diagnosis and 2014;9(3):733-747. treatment. Pediatr Infect Dis J. 1998;17(9):827-834. 24. Garbutt JM, Conlon B, Sterkel R, et al. The comparative 3. Weinberg GA, Hall CB, Iwane MK, et al.; New Vaccine Sur- effectiveness of prednisolone and dexamethasone for veillance Network. Parainfluenza virus infection of young children with croup: a community-based randomized trial. children: estimates of the population-based burden of hos- Clin Pediatr (Phila). 2013;52(11):1014-1021. pitalization. J Pediatr. 2009;154(5):694-699. 25. Bjornson C, Russell K, Vandermeer B, Klassen TP, John- 4. Denny FW, Murphy TF, Clyde WA Jr., Collier AM, Hender- son DW. Nebulized epinephrine for croup in children. son FW. Croup: an 11-year study in a pediatric practice. Cochrane Database Syst Rev. 2013;(10):CD006619. Pediatrics. 1983;71(6):871-876. 26. Eghbali A, Sabbagh A, Bagheri B, Taherahmadi H, Kahbazi M. 5. Petrocheilou A, Tanou K, Kalampouka E, Malakasioti G, Efficacy of nebulized L-epinephrine for treatment of Giannios C, Kaditis AG. Viral croup: diagnosis and a treat- croup: a randomized, double-blind study. Fundam Clin ment algorithm. Pediatr Pulmonol. 2014;49(5):421-429. Pharmacol. 2016;30(1):70-75. 6. Bjornson CL, Johnson DW. Croup in children. CMAJ. 27. Moore M, Little P. Humidified air inhalation for treating 2013;185(15):1317-1323. croup: a systematic review and meta-analysis. Fam Pract. 7. Lee DR, Lee CH, Won YK, et al. Clinical characteristics of 2007;24(4):295-301. children and adolescents with croup and epiglottitis who 28. Scolnik D, Coates AL, Stephens D, Da Silva Z, Lavine E, visited 146 emergency departments in Korea. Korean Schuh S. Controlled delivery of high vs low humidity vs J Pediatr. 2015;58(10):380-385. mist therapy for croup in emergency departments: a ran- 8. Rosekrans JA. Viral croup: current diagnosis and treatment. domized controlled trial. JAMA. 2006;295(11):1274-1280. Mayo Clin Proc. 1998;73(11):1102-1106. 29. Moraa I, Sturman N, McGuire T, van Driel ML. Heliox for 9. Marx A, Török TJ, Holman RC, Clarke MJ, Anderson LJ. croup in children. Cochrane Database Syst Rev. 2013;(12): Pediatric hospitalizations for croup (laryngotracheo- CD006822. 580 American Family Physician www.aafp.org/afp Volume 97, Number 9 ◆ May 1, 2018