What is the appropriate evaluation and management for a patient presenting with unilateral or bilateral cheek swelling, pain on chewing, fever, limited mouth opening, and possible purulent discharge from Stensen's duct (parotid duct) suggestive of acute parotitis?

Acute Parotitis: Evaluation and Management

Immediate Clinical Assessment

For a patient presenting with unilateral or bilateral parotid swelling, pain on chewing, fever, and possible purulent discharge from Stensen's duct, immediately assess for facial nerve function, as any facial weakness indicates either malignancy or serious complication requiring emergency evaluation. 1

Key Clinical Features to Document

• Unilateral vs. bilateral involvement: Bilateral swelling suggests mumps, Sjögren's syndrome, or systemic autoimmune process, while unilateral involvement more commonly indicates bacterial infection or mass lesion 1, 2
• Purulent discharge from Stensen's duct: Indicates bacterial parotitis; massage the parotid gland for 30 seconds and observe the duct opening for purulent drainage 3, 4
• Fever and constitutional symptoms: Suggest infectious etiology or potentially lymphoma 1
• Pain characteristics: Painful swelling typically indicates infection or inflammation, while painless masses raise concern for malignancy 1
• Vaccination history: Mumps should be considered even in vaccinated individuals, as vaccine efficacy is approximately 88% and breakthrough infections occur 3

Diagnostic Workup

Microbiologic Testing

For suspected bacterial parotitis, obtain culture from purulent discharge at Stensen's duct to guide antibiotic therapy, as Staphylococcus aureus accounts for 80% of cases, followed by streptococci, anaerobes, and gram-negative bacilli. 5

• For suspected mumps, obtain an oral or buccal swab around the affected parotid gland and Stensen duct for viral culture or NAAT (nucleic acid amplification test), as this is the preferred specimen source 3
• Collect serum for mumps IgM antibodies and IgG titers (acute and convalescent phases 5-10 days apart), though previously vaccinated patients may not develop detectable IgM response 3
• Critical pitfall: Previously immunized patients with mumps may not mount an IgM response, requiring viral isolation or RNA detection for confirmation 3

Imaging Algorithm

Order high-frequency ultrasound (≥12 MHz) with color Doppler as the initial imaging study to distinguish parotid versus extraparotid location, identify abscess formation, and characterize suspicious features. 1

• Proceed immediately to MRI with and without IV contrast if deep lobe involvement is suspected, facial nerve dysfunction is present, ultrasound shows indeterminate or concerning features, or additional palpable neck lymph nodes are identified 1, 6
• Ultrasound has significant limitations for deep lobe parotid lesions, which are not well visualized compared to superficial lobe masses 7

When to Obtain Tissue Diagnosis

Perform fine needle aspiration biopsy (FNAB) for any mass that persists beyond acute infection treatment to distinguish between inflammatory, infectious, autoimmune, and malignant causes. 1

• Use ultrasound-guided FNA rather than palpation-guided to increase specimen adequacy, target solid components in heterogeneous masses, and reduce inadequacy rates 1
• Critical caveat: Imaging alone cannot definitively distinguish benign from malignant parotid masses; histologic confirmation is essential 7, 6

Initial Management Strategy

For Presumed Bacterial Parotitis

Initiate broad-spectrum antibiotics immediately covering Staphylococcus aureus and anaerobes, combined with conservative measures including gland massage, warm compresses, sialogogues (lemon drops or other agents to stimulate saliva), and aggressive hydration. 1, 4

• The most common pathogens are Staphylococcus aureus (80% of cases) and anaerobic bacteria including pigmented Prevotella, Porphyromonas, Fusobacterium, and Peptostreptococcus species 5
• Gram-negative organisms (E. coli, Klebsiella, Pseudomonas) are often seen in hospitalized or immunocompromised patients 5
• Monitor closely for abscess formation, which would require surgical drainage 1, 8

For Suspected Mumps

Report the case to the community healthcare service immediately, as mumps is a reportable disease, and isolate the patient to prevent aerogenic transmission. 2

• Mumps virus RNA may be detected from parotid duct swabs from symptom onset until 5-9 days after onset 3
• Recent outbreaks have occurred predominantly among young, vaccinated adults, demonstrating that vaccination does not provide absolute protection 2

Conservative Management Approach

For chronic or recurrent parotitis, particularly in patients with Sjögren's syndrome or hyposalivation, conservative approaches including gland massage, local application of superficial moist heat, and periodic pus drainage should be considered as first-line management before antibiotics. 4

• This approach has shown success even in cases that did not respond to oral or intravenous antibiotics 4
• Maintenance of good oral hygiene, adequate hydration, and sialogogues may reduce the occurrence of suppurative parotitis 5

Follow-Up Protocol

Re-evaluate within 48-72 hours of initiating antibiotics, and obtain ultrasound to assess for abscess or underlying mass if symptoms persist or worsen. 1

• Any residual mass after infection resolution requires tissue diagnosis 1
• Consider autoimmune workup including Sjögren's antibodies if bilateral involvement or recurrent episodes occur 1

Red Flags Requiring Urgent Surgical Consultation

Immediately refer to otolaryngology if facial nerve palsy develops, abscess formation is identified on imaging, rapidly enlarging mass despite antibiotic therapy, or histology confirms malignancy. 1

• Facial nerve dysfunction may indicate malignancy with perineural invasion or complicated infection requiring surgical intervention 1, 6
• Once an abscess has formed, surgical drainage is required 5

Special Populations

Pediatric Recurrent Parotitis

• Recurrent parotitis in children aged 3-6 years is likely caused by congenital abnormality of salivary ducts with recurrent ascending infection 9
• Symptoms typically peak in the first year of school and usually subside at puberty, with most patients symptom-free by age 22 9
• Treatment is conservative with expectant management; aggressive interventions are justified only for adults with persistent problems 9

Patients with Sjögren's Syndrome

• Bilateral parotid involvement with recurrent swelling is characteristic of Sjögren's syndrome 1
• These patients have increased lymphoma risk, as MALT lymphoma and other marginal zone lymphomas can present as parotid masses 1
• Decreased salivary flow renders glands prone to retrograde colonization with oral microflora 4