Larry B. Mellick, MD, FAAP, FACEP
Professor of Emergency Medicine and Pediatrics
Medical College of Georgia
Children's Hospital of Georgia
Georgia Regents University, Augusta

Pearl: Pediatric sinusitis is essentially a clinical diagnosis based on three different criteria, and the treatment recommendations are changing.

Case: A 15-month-old female infant presents for evaluation of a fever that began yesterday. As you question the patient's mother, she mentions that the toddler has had nasal drainage and signs of a respiratory tract infection for more than a week. In the last 24 hours, however, she has become febrile and more irritable. On examination, her temperature is 39 degrees. Auscultation of the lungs demonstrates clear lung sounds, and her cough is not productive sounding. There are no signs of an ear infection, and the child has a purulent nasal drainage from both nares. You discuss the diagnostic possibilities with the mother and establish a treatment plan.

Discussion: The diagnosis of sinusitis in adults is difficult enough, but it is even more of a challenge in children. And doesn't sinusitis occur commonly with every upper respiratory tract infection? Furthermore, some question whether young children even have sinuses. While it's true that young children don't have all of their sinuses, they do have sinuses, and the sinuses can become infected. The maxillary sinuses are present at birth and expand rapidly during the first four years of life. The ethmoid sinuses are also present at birth. The sphenoid sinuses develop during the first two years of life, and the frontal sinuses can be radiologically differentiated from the ethmoid sinuses by 6 to 8 years of age. By 12 years of age, the development of the nasal cavity and the paranasal sinuses is nearly completed and they have reached adult proportions. One way to remember the sequence of how sinuses develop is the following mnemonic:

"Maxillaries Early, Sphenoids Follow" = 1. Maxillary, 2. Ethmoids, 3. Sphenoids, 4. Frontals

In the past, physicians have tried to diagnose sinusitis with plain radiographs. Plain radiographs can show clear sinuses or an abnormal study. The problems are radiation exposure and differentiating sinusitis from acute viral rhinosinusitis, which usually precedes the acute bacterial rhinosinusitis (ABRS). About 80% of bacterial sinus infections are caused by a predisposing and preceding viral rhinosinusitis. Allergic inflammation is responsible for the other 20%.

The draining sinus ostia swell, obstruction occurs, and normal mucociliary clearance is compromised. Imaging studies (plain-film radiography, computed tomography [CT], magnetic resonance imaging [MRI], and ultrasonography) will show signs of sinus inflammation, but are lacking in clinical specificity (viral vs. bacterial). However, if one clinically suspects ABRS based on presentation, the associated abnormal radiographs have been demonstrated to correlate with sinus aspirates of pathogenic bacteria.¹ Imaging studies such as a CT scan or MRI are appropriate for children with persistent or recurrent disease that doesn't respond to medical management or if complications of sinusitis, such as an intracranial abscess or orbital involvement, are suspected.

Consequently, the consensus by the IDSA Clinical Practice Guideline, American College of Radiology, and others who study the topic is that the diagnosis should be made clinically in children.^2,3,4,5 Unfortunately, sinusitis in children is much less specific in signs and symptoms, and tenderness is not a typical sign that is observed. Fortunately, consensus opinions have been developed with the evidence currently available to help us know when to treat children for ABRS. The clinical criteria recommended are essentially three different patterns of presentation that are more likely than not to be acute bacterial rhinosinusitis. These three patterns are as follows: (Figure 1)

1. CHRONIC: Symptoms of upper respiratory tract infection that persist for more than 10 but fewer than 30 days without subsiding. The rhinorrhea may be thick or thin, watery, mucoid, or purulent. The child may be only mildly ill, and fever, if present, is low grade.
2. SEVERE: Severe symptoms at onset such as a high fever (> 39° C [102° F]) of at least 3 to 4 days' duration and the rhinorrhea is purulent (thick, colored, and opaque).
3. WORSENING: Children in this category present with a biphasic illness and worsening symptoms after a period of improvement (double sickening). Fever, increased nasal discharge, and daytime cough will typically become manifest about a week after the onset of illness.

Treatment guidelines are changing because the prevalence and antimicrobial susceptibility profiles of bacterial isolates associated with ABRS are changing.^3,4 Additionally, the use of conjugated vaccines for Streptococcus pneumoniae has resulted in the emergence of non-vaccine serotypes to be more prevalently associated with ABRS. The IDSA guidelines now recommend that amoxicillin-clavulanate be used rather than amoxicillin alone as empiric antimicrobial therapy for ABRS in children. The duration of treatment is 10 to 14 days or until the patient is symptom-free plus another seven days.⁴ High-dose amoxicillin-clavulanate (90 mg per kilogram per day, administered in two doses) is recommended in geographic regions with high endemic rates of invasive penicillin-nonsusceptible S. pneumoniae, those with severe infection, threat of suppurative complications, attendance at daycare, recent hospitalization, and antibiotic use within the past month or if the patient is immunocompromised. If there are no risk factors, then the standard-dose amoxicillin-clavulanate (40 mg per kilogram per day, administered in two doses) is recommended.

Summary: The diagnosis of sinusitis in children is a clinical diagnosis and antibiotic treatment recommendations for ABRS have adapted to changing bacterial antibiotic resistance patterns. Haemophilus influenzae has become more common and Streptococcus pneumoniae less common as bacterial agents associated with sinusitis in children. Rates of beta-lactamase production by H. Influenzae have increased in many geographic areas.⁴

References:

1. Wald ER, Milmoe GJ, Bowen A, Ledesma-Medina J, et al. Acute maxillary sinusitis in children. N Engl J Med. 1981;304(13):749-754.
2. Anzai Y, Paladin A. Diagnostic imaging in 2009: Update on evidence-based practice of pediatric imaging. What is the role of imaging in sinusitis? Pediatr Radiol. 2009;39 Suppl 2:S239-S241.
3. Chow AW, Benninger MS, Brook I, Brozek JL, et al, Infectious Diseases Society of America. IDSA clinical practice guideline for acute bacterial rhinosinusitis in children and adults. Clin Infect Dis. 2012;54(8):e72-e112.
4. DeMuri GP, Wald ER. Clinical practice. Acute bacterial sinusitis in children. N Engl J Med. 2012;367(12):1128-1134.
5. Setzen G, Ferguson BJ, Han JK, et al. Clinical consensus statement: appropriate use of computed tomography for paranasal sinus disease. Otolaryngol Head Neck Surg. 2012;147(5):808-816.

Online Resources:

1. http://emedicine.medscape.com/article/873149-overview