What are the risk factors for acute bacterial rhinosinusitis in children, particularly those with a history of allergies, asthma, or previous respiratory infections?

Risk Factors for Acute Bacterial Rhinosinusitis in Children

The primary risk factors for developing acute bacterial rhinosinusitis (ABRS) in children are recent viral upper respiratory infection (the most common predisposing factor), allergic rhinitis, attendance at child care, recent antibiotic use within 30 days, and age younger than 2 years. 1

Infectious and Environmental Risk Factors

Viral Upper Respiratory Infection

• Viral URI is the single most important predisposing factor for ABRS in children, occurring when inflammation of the nasal and sinus mucosal lining from viral infection creates conditions for bacterial superinfection. 1
• Approximately 8% of viral upper respiratory infections are complicated by acute viral sinusitis, which can then progress to bacterial sinusitis. 1
• The typical progression involves initial viral infection followed by bacterial superinfection when symptoms persist beyond 10 days, worsen after initial improvement, or present with severe onset. 1

Child Care Attendance

• Children attending day care have significantly increased risk for ABRS due to higher exposure to respiratory pathogens and increased frequency of viral URIs. 1
• Day care attendance is specifically identified as a risk factor for antibiotic-resistant organisms, particularly β-lactamase-positive Haemophilus influenzae and penicillin-nonsusceptible Streptococcus pneumoniae. 1

Recent Antibiotic Exposure

• Receipt of antimicrobial treatment within the previous 30 days substantially increases risk for both ABRS development and antibiotic-resistant bacterial pathogens. 1
• This risk factor is critical when selecting initial antibiotic therapy, as it predicts organisms likely resistant to amoxicillin. 1

Age-Related Risk Factors

• Children younger than 2 years have elevated risk for both ABRS and antibiotic-resistant organisms. 1
• This age group experiences 6-8 URIs per year on average, creating multiple opportunities for bacterial superinfection. 2
• Infants under 6 months can develop severe complications from nasal congestion due to obligate nasal breathing. 2

Allergic and Atopic Conditions

Allergic Rhinitis

• Allergic rhinitis is the second most common predisposing factor for ABRS after viral infection, causing mucosal inflammation and impaired sinus drainage. 1
• Children with documented allergic rhinitis should receive intranasal steroids and nonsedating antihistamines to reduce ABRS risk. 1
• However, allergic rhinitis is uncommon as a cause of chronic nasal symptoms in children under 2 years of age. 2

Asthma and Atopic Diathesis

• Children with asthma and other atopic conditions (eczema, atopic dermatitis) may have increased susceptibility to ABRS, though this is primarily through the mechanism of allergic rhinitis rather than asthma itself. 3
• The presence of atopic stigmata (nasal crease, allergic shiners, eczematous changes) should be documented when evaluating children with recurrent respiratory symptoms. 3

Underlying Medical Conditions

Recurrent Acute Bacterial Sinusitis (RABS)

Children with ≥4 episodes of ABRS per year meeting strict diagnostic criteria warrant evaluation for the following underlying conditions: 1

• Immunodeficiency: Quantitative immunoglobulin A and immunoglobulin G deficiency 1
• Cystic fibrosis: Should be considered in children with recurrent sinopulmonary infections 1
• Gastroesophageal reflux disease: Can contribute to chronic inflammation and recurrent infections 1
• Ciliary dysfunction: Dysmotile cilia syndrome impairs normal mucociliary clearance 1

Anatomical Abnormalities

• Nasal airway obstruction from various causes increases ABRS risk. 1
• Specific anatomical factors include: septal deviation, nasal polyps, concha bullosa (pneumatization of middle turbinate), atypical ethmoid cells with compromised drainage, lateralized middle turbinate, and intrinsic ostiomeatal anomalies. 1
• Adenoidal hypertrophy is the most common acquired anatomic cause of nasal obstruction in young children and can predispose to ABRS. 2
• Genetic or acquired craniofacial abnormalities require evaluation with contrast-enhanced CT, MRI, or endoscopy. 1

Odontogenic Infections

• Dental infections can lead to maxillary sinusitis in children, though this is less common than other predisposing factors. 1

Risk Stratification for Antibiotic Resistance

When selecting initial antibiotic therapy, the following combination of risk factors predicts organisms likely resistant to standard-dose amoxicillin: 1

• Age younger than 2 years
• Day care attendance
• Antibiotic use within previous 30 days
• Geographic area with high prevalence (>10%) of penicillin-nonsusceptible S. pneumoniae

Children with these risk factors should receive high-dose amoxicillin-clavulanate (90 mg/kg/day of amoxicillin component) rather than standard-dose amoxicillin as first-line therapy. 1

Important Clinical Caveats

• Previous respiratory infections alone do not constitute a specific risk factor unless they represent recurrent ABRS (≥4 episodes/year) warranting evaluation for underlying conditions. 1
• The presence of purulent nasal discharge does not indicate bacterial infection, as nasal discharge commonly transitions from clear to purulent during uncomplicated viral URIs. 3, 4
• Most children in day care experience 6-8 URIs per year, and chronic nasal congestion is typically due to sequential viral infections rather than ABRS or allergic rhinitis. 2
• Imaging abnormalities alone are not sufficient for diagnosis, as 68% of symptomatic children with viral URI and 42% of healthy children have significant sinus abnormalities on imaging. 1