Can influenza cause parotitis in children?

Can Influenza Cause Parotitis in Children?

Yes, influenza can cause parotitis in children, though it is a rare complication. 1

Evidence for Influenza-Associated Parotitis

The British Infection Society, British Thoracic Society, and Health Protection Agency guidelines explicitly identify parotitis as a recognized complication of influenza A infection, though they classify it as "rarely encountered." 1 While these guidelines note that parotitis is more commonly documented in adults, the complication does occur across all age groups. 1

Recent research from Argentina provides compelling evidence that influenza can present with parotitis in children: In a 2017 study of 22 pediatric parotitis cases, 68.2% tested positive for influenza virus (93% influenza A H3N2, 7% influenza B). 2 Importantly, 74% of these children presented with concurrent influenza-like illness alongside parotitis, though the study emphasizes that parotitis can occur even without respiratory symptoms. 2

Clinical Presentation and Diagnosis

When influenza causes parotitis, children typically present with:

• Swelling and pain in one or both parotid glands 2
• Fever, headache, and muscle aches 2
• Often concurrent respiratory symptoms (cough, rhinorrhea), though these may be absent 2
• Mild clinical course with swelling lasting approximately 5 days on average 2

The key diagnostic challenge is distinguishing influenza parotitis from other causes, particularly mumps. 2, 3 A confirmed case of influenza A parotitis in 2007 demonstrated the importance of: (1) confirming influenza by subtyping, (2) documenting mumps immunity serologically, and (3) observing full recovery without antibiotics. 3

Differential Diagnosis Considerations

While influenza is a recognized viral cause of parotitis, other etiologies must be considered:

• Viral causes: Paramyxovirus (mumps), Epstein-Barr virus, coxsackievirus, parainfluenza viruses 4
• Bacterial suppurative parotitis: Primarily Staphylococcus aureus, anaerobes (Peptostreptococcus, Bacteroides, pigmented Prevotella/Porphyromonas species) 5, 4
• Less common bacterial causes: Streptococcus pneumoniae, gram-negative bacilli, particularly in hospitalized patients 5, 4

Management Approach

For suspected influenza-associated parotitis:

1. Confirm influenza diagnosis through rapid testing or PCR, as this guides antiviral treatment decisions and has public health implications. 2, 3

2. Document mumps immunity status to exclude mumps as the etiology, especially in vaccinated children. 3

3. Consider oseltamivir if the child has been symptomatic for <48 hours (ideally) or up to 6 days in high-risk children, though evidence for benefit beyond 48 hours is limited. 6

4. Maintain hydration and provide supportive care. 4

5. Avoid antibiotics initially if the presentation is consistent with viral parotitis and the child appears well. 3 However, if bacterial suppurative parotitis develops (indicated by severe toxicity, persistent high fever, or abscess formation), empiric antimicrobial therapy covering both aerobic and anaerobic bacteria is required. 4

6. Monitor for complications: While the Argentine study showed no complications in influenza-associated parotitis cases 2, children with influenza remain at risk for other serious complications including bacterial pneumonia, encephalopathy, and otitis media. 6, 7

Clinical Pitfalls to Avoid

• Do not dismiss parotitis as automatically being mumps in vaccinated children without considering influenza, especially during influenza season. 2, 3
• Do not overlook influenza as a cause of parotitis even when respiratory symptoms are absent. 2
• Do not delay influenza testing in children presenting with parotitis during influenza season, as this has both treatment and public health implications. 3
• Never use aspirin for fever control in children with influenza due to Reye's syndrome risk; use acetaminophen instead. 6

Public Health Considerations

Systematic surveillance of influenza-associated parotitis is recommended to better understand the epidemiology of this atypical presentation. 2 Healthcare providers should maintain awareness of atypical influenza presentations like parotitis due to time-sensitive pharmacologic management and potential public health implications. 3