Most Common Causes of Submandibular Sialadenitis
The most common causes of submandibular sialadenitis are ductal obstruction (often by salivary stones), bacterial infection (predominantly Staphylococcus aureus), and mechanical compression or positioning issues affecting salivary flow. 1, 2, 3
Obstructive Causes
- Salivary stones (sialolithiasis) - frequently present as acute pain and swelling in the submandibular gland 4
- Ductal strictures or stenosis leading to reduced salivary flow and subsequent infection 3
- Mechanical compression of Wharton's duct, particularly during prolonged head and neck positioning (as seen in skull base surgeries) 5
Infectious Causes
- Bacterial infection - Staphylococcus aureus is the predominant pathogen (found in 53% of cases) 1, 2
- Viridans streptococci - second most common bacterial cause (31% of cases) 1
- Viral infection - paramyxovirus (mumps) is a common viral etiology 3
- Both aerobic and anaerobic pathogens may be involved in bacterial sialadenitis 2
Predisposing Factors
- Dehydration - reduces salivary flow and increases risk of infection 2
- Advanced age - elderly patients have increased susceptibility 6
- Xerogenic medications that reduce saliva production 2
- Post-surgical complications, particularly following skull base neurosurgery with prolonged head rotation 5
- Underlying salivary gland diseases associated with reduced secretion 2
Rare Causes
- Actinomycosis infection 2
- Tuberculosis affecting the salivary glands 2
- Atypical mycobacterial infections 2
- Post-radiation sialadenitis in patients receiving head and neck radiotherapy 3
Pathophysiologic Mechanisms
- Acalculous obstruction of the submandibular duct (Wharton's duct) is a key mechanism, particularly in post-surgical cases 5
- Ischemia or reperfusion injury from compression of the facial or lingual artery 5
- Retrograde infection ascending through the salivary ducts, especially in dehydrated patients 2
- Compression of the tongue by endotracheal tubes may precipitate salivary duct obstruction 5
Clinical Pearls
- Acute submandibular sialadenitis typically presents with swelling, pain, tenderness, fever, and occasionally difficulty opening the mouth 6
- In post-surgical cases, submandibular swelling typically occurs within 4 hours of extubation 5
- Airway compromise is a potentially life-threatening complication requiring immediate intervention 7
- Neurologic complications including brachial plexopathy, facial nerve palsy, and Horner syndrome may occur due to inflammatory compression of adjacent structures 5, 7