What is the most likely diagnosis and appropriate initial management for a 72-year-old man with acute unilateral submandibular gland swelling and pain that improves with NSAIDs, without fever, chills, or pain on mandibular opening or clenching?

Acute Unilateral Submandibular Swelling in a 72-Year-Old Man

This presentation is most consistent with obstructive sialadenitis (likely sialolithiasis), and initial management should include hydration, sialagogues (lemon drops or sour candies), warm compresses, gland massage, and empiric antibiotics targeting oral flora while arranging urgent imaging and specialist referral.

Differential Diagnosis and Risk Stratification

The clinical presentation requires immediate assessment for malignancy risk, as any neck mass in an adult without clear infectious etiology that persists ≥2 weeks represents increased malignancy risk 1. However, several features in this case suggest a benign inflammatory process:

Features Suggesting Benign Etiology:

• Acute onset (not chronic/progressive)
• Pain responsive to NSAIDs (inflammatory rather than neoplastic)
• No trismus (absence of pain with jaw opening/clenching argues against temporomandibular joint pathology or deep space infection)
• Absence of systemic symptoms (no fever/chills reduces likelihood of acute bacterial infection)

Features That Would Increase Malignancy Concern:

• Size >1.5 cm, firm consistency, fixation to adjacent tissues, or skin ulceration would mandate urgent CT imaging with contrast 1
• Duration >2 weeks without fluctuation 1
• In this 72-year-old patient, age itself is a risk factor for malignancy that cannot be ignored

Most Likely Diagnosis: Obstructive Sialadenitis

The submandibular gland is the most common site for sialolithiasis, accounting for the majority of salivary stone cases 2, 3, 4. The clinical picture of acute unilateral submandibular swelling with pain in an elderly patient strongly suggests obstructive sialadenitis, most commonly due to:

• Sialolithiasis (salivary stones) - typically 5-10 mm, though giant stones >10 mm can occur 4
• Ductal stenosis or mucus plugging
• Less commonly, chronic inflammation without stones 3

The absence of meal-related pain exacerbation is not exclusionary, as chronic partial obstruction may present with constant rather than intermittent symptoms 5.

Initial Diagnostic Workup

Immediate Physical Examination Must Include:

• Bimanual palpation of the submandibular gland (one finger intraorally along the floor of mouth, one externally) to assess for stones, masses, or tenderness 5
• Inspection of Wharton's duct opening (floor of mouth near frenulum) for purulent discharge, erythema, or visible stone 3
• Assessment for palpable stone along the duct course
• Evaluation for fixation, firmness, and size to stratify malignancy risk 1

Imaging Strategy:

Given the patient's age (72 years) and the need to exclude malignancy, CT neck with contrast should be obtained 1. This serves dual purposes:

• Identifies sialoliths (radiopaque in 80% of submandibular stones)
• Excludes malignancy in this at-risk age group
• Assesses for abscess formation or deep space involvement

Ultrasound can be used as an adjunct but should not delay definitive imaging in this age group 4, 5.

Initial Management

Conservative Measures (First-Line):

• Aggressive hydration (oral or IV if unable to tolerate PO) 3
• Sialagogues - lemon drops, sour candies, or citrus to stimulate salivary flow 3
• Warm compresses to the affected gland 3
• Gland massage (once acute tenderness subsides) from posterior to anterior along the duct 3
• Continue NSAIDs for pain and inflammation (already showing response) 2, 3

Antibiotic Therapy:

Empiric oral antistaphylococcal antibiotics should be initiated while awaiting culture results 3. Appropriate choices include:

• Amoxicillin-clavulanate (covers oral flora including Staphylococcus aureus and anaerobes)
• Clindamycin (if penicillin allergic)

The rationale: Even without overt signs of bacterial superinfection (fever, purulent discharge), obstruction creates stasis predisposing to secondary infection 3.

Critical Pitfalls to Avoid

NSAID-Related Considerations:

In this 72-year-old patient on NSAIDs, assess for gastrointestinal bleeding risk factors 6, 7:

• Concurrent antiplatelet or anticoagulant use (80% of UGIB patients use such medications) 7
• History of peptic ulcer disease
• Consider PPI co-prescription - only 8.9% of at-risk patients receive appropriate prophylaxis 7
• Celecoxib has the lowest GI bleeding risk (OR 1.16) if NSAID continuation is needed 6

Do Not Delay Specialist Referral:

• Otolaryngology consultation should be arranged urgently (within days, not weeks)
• If no improvement within 48-72 hours of conservative management, escalate care
• Any concern for airway compromise requires immediate ENT evaluation (though not typical for submandibular pathology unless massive swelling)

Malignancy Exclusion:

Document a clear follow-up plan 1. If imaging reveals:

• Solid mass without stone → Fine-needle aspiration biopsy mandatory
• Persistent swelling after stone removal/treatment → Biopsy to exclude tumor
• Any "red flag" features (fixation, rapid growth, cranial nerve deficits) → Expedited head and neck oncology referral

Follow-Up Criteria

Advise the patient to return immediately if 1:

• Fever develops (suggests progression to acute suppurative sialadenitis)
• Swelling worsens or spreads to neck/floor of mouth
• Difficulty swallowing or breathing
• No improvement within 48-72 hours of treatment

Scheduled reassessment within 1 week to confirm resolution or finalize diagnosis based on imaging results 1.