What is the diagnosis and treatment of bilateral parotitis?

Diagnosis and Management of Bilateral Parotitis

Bilateral parotitis is diagnosed clinically by the presence of tender swelling of both parotid glands lasting ≥2 days, with mumps virus being the most common viral cause, and requires supportive care for viral etiologies or broad-spectrum antibiotics covering Staphylococcus and Streptococcus species for bacterial causes. 1

Clinical Diagnosis

The diagnosis of bilateral parotitis is primarily clinical and does not require imaging in straightforward cases. Key diagnostic features include:

• Bilateral tender, self-limited swelling of the parotid glands lasting ≥2 days, often accompanied by pain and fever 1
• Pain on swallowing is a typical accompanying symptom 1
• Systemic symptoms may include fever, headache, malaise, myalgia, and anorexia, which often precede the parotid swelling 1
• In mumps specifically, parotitis typically develops 16-18 days after exposure 1

A critical clinical distinction is determining whether the parotitis is viral or bacterial in origin, as this fundamentally changes management:

Viral Parotitis Features:

• Mumps is the most common viral cause and typically affects children aged 2-9 years 1
• Only 30-40% of mumps infections produce typical acute parotitis; 15-20% are asymptomatic 1
• Bilateral presentation is more common with viral etiologies 1

Bacterial Parotitis Features:

• More common in patients with hyposalivation (e.g., Sjögren syndrome) 1
• The most common pathogens are Staphylococcus aureus and anaerobic bacteria (including Prevotella, Porphyromonas, Fusobacterium, and Peptostreptococcus species) 2
• Gram-negative organisms (E. coli, Klebsiella) are often seen in hospitalized patients 2

Diagnostic Testing

For suspected mumps (viral parotitis), obtain:

• Serum mumps IgM antibodies (positive in acute infection) 1
• Paired acute and convalescent serum for mumps IgG (4-fold rise indicates recent infection) 1
• Buccal swab around affected parotid gland and Stensen's duct for viral culture or nucleic acid amplification testing 1

Imaging is reserved for specific clinical scenarios:

• High-frequency ultrasound (≥12 MHz) with Doppler is the first-line imaging if abscess formation is suspected, to differentiate solid from cystic lesions and identify complications 3
• CT with IV contrast is useful for evaluating parotid inflammation and possible abscess formation when clinical examination suggests complications 1
• Imaging is not routinely needed for straightforward bilateral parotitis with typical viral features 1, 4

Treatment Algorithm

For Viral Parotitis (Mumps):

Supportive care is the mainstay of treatment:

• Hydration maintenance 1
• Analgesics for pain relief 1
• Isolation of infected individuals to prevent spread 1
• No antibiotics are indicated for uncomplicated viral parotitis 1

For Bacterial Parotitis:

Initiate broad-spectrum intravenous antibiotic therapy:

• Coverage must include Staphylococcus species and Streptococcus species, which are the most frequent pathogens 3
• Anaerobic coverage should be included given the high prevalence of anaerobic bacteria 2
• Maintenance of hydration and good oral hygiene 2
• If abscess formation is confirmed, surgical drainage is required 3, 2

For Chronic Recurrent Parotitis:

• Initial management includes prolonged medical therapy with hydration and antibiotics during acute exacerbations 5
• Surgical parotidectomy may ultimately be required for disease control when medical management fails 5

Key Differential Diagnoses to Consider

Non-infectious causes that can mimic bilateral parotitis:

• Sjögren syndrome may present with recurrent parotitis 1
• Immune-related adverse events from checkpoint inhibitors can cause parotitis 1
• Mechanical causes such as retrograde air flow (e.g., during CPAP therapy) can cause bilateral parotitis 6
• Sarcoidosis can affect parotid glands bilaterally 7

Complications to Monitor

Mumps-related complications include:

• Orchitis in up to 38% of postpubertal men 1
• Aseptic meningitis in 4-6% of clinical mumps cases 1
• Sensorineural deafness (can be sudden, bilateral, and permanent) 1

Prevention

MMR vaccination is highly effective in preventing mumps and should be emphasized as the primary preventive measure 1

Common Pitfalls to Avoid

• Do not routinely order imaging for straightforward bilateral parotitis with typical viral features, as the diagnosis is clinical 1, 4
• Do not prescribe antibiotics for viral parotitis, as this provides no benefit and contributes to antimicrobial resistance 1
• Do not delay surgical drainage once abscess formation is confirmed, as this facilitates recovery 3
• Ensure adequate hydration and oral hygiene to reduce the risk of bacterial superinfection 2
• Consider non-infectious etiologies (Sjögren syndrome, drug reactions, mechanical causes) when the clinical picture does not fit typical infectious parotitis 1, 6