Submandibular Sialadenitis

Submandibular sialadenitis is inflammation of the submandibular gland, usually caused by obstruction of Wharton duct by a stone, stricture or mucus plug, followed by bacterial infection. The gland produces thick, mucous saliva that flows uphill against gravity, which favours stone formation.

• Stones account for most cases.
• Bacteria are Staphylococcus aureus, streptococci and anaerobes.
• Dehydration, diuretics and anticholinergic drugs add risk.

Pain and swelling under the jaw, worse at meals and settling afterwards in early disease, then persistent tender swelling with fever.

• Bimanual palpation may feel a stone in the floor of the mouth and pus may emerge from the duct opening beside the frenulum.
• Differential diagnosis: submandibular lymphadenitis, dental abscess, Ludwig angina, sialolithiasis, tumour (pleomorphic adenoma, carcinoma), tuberculosis, lymphoma, branchial cyst, IgG4 related disease.
• Complications: abscess, spread to the floor of the mouth and airway, chronic sclerosing sialadenitis, ductal stricture.

Clinical, confirmed by imaging.

• Ultrasound identifies stones larger than 2 mm and gland changes; CT for suspected deep infection.
• Occlusal radiograph shows radiopaque stones.
• Pus culture, full blood count, CRP and glucose.

Relieve obstruction and infection.

• Supportive: fluids, warm compress, gland massage, sour stimulants such as lemon, oral hygiene, stopping drying drugs.
• Pharmacological: amoxicillin clavulanate 625 mg three times daily for 7 days, or flucloxacillin 500 mg four times daily; clindamycin 300 mg four times daily if penicillin allergic; IV flucloxacillin 1 to 2 g every 6 hours with metronidazole 500 mg every 8 hours for severe disease. Ibuprofen 400 mg every 8 hours and paracetamol 1 g every 6 hours.
• Procedures: manual removal of a stone near the duct opening; transoral duct incision for anterior stones; sialendoscopy with basket retrieval; incision and drainage of abscess; submandibular gland excision for recurrent stones or chronic disease, with care of the marginal mandibular and lingual nerves.
• Special groups: pregnancy, amoxicillin clavulanate and ultrasound; children, flucloxacillin by weight and ENT review; diabetes, glucose control; HIV, culture and consider mycobacterial infection.
• Red flags: floor of mouth swelling, difficulty breathing or swallowing, drooling, trismus, fever with spreading neck swelling, hard fixed mass.
• Follow-up: review in 48 hours; arrange definitive stone or gland management after the infection settles.