Submandibular Gland Infection

Submandibular gland infection (acute bacterial sialadenitis) is infection of the submandibular salivary gland, nearly always secondary to obstruction of Wharton duct by a stone (sialolithiasis, 80 percent of salivary stones). Organisms are Staphylococcus aureus, streptococci and oral anaerobes.

• Risk factors: stones, dehydration, poor oral hygiene, anticholinergic drugs, Sjogren syndrome, radiotherapy, duct stenosis.
• Most common in middle aged adults.

Painful swelling of the floor of the mouth and angle of the mandible, worse with eating, with erythema, tenderness, fever and pus from the Wharton duct opening beside the frenulum.

• Bimanual palpation may reveal a stone in the duct.
• Differential diagnosis: submandibular lymphadenitis, Ludwig angina, dental abscess, tumour (pleomorphic adenoma, adenoid cystic carcinoma), Sjogren syndrome, ranula, mumps, HIV salivary gland disease, sarcoidosis, tuberculous node.
• Complications: abscess, spread to submandibular and sublingual spaces, Ludwig angina (airway compromise), chronic sclerosing sialadenitis, ductal stricture, sepsis.

Clinical, with imaging.

• Ultrasound for stone, abscess and gland swelling; CT with contrast for deep infection or airway concern; plain occlusal radiograph for radio-opaque stones.
• Culture of pus from the duct; full blood count, CRP, urea, glucose; sialendoscopy for later diagnosis and treatment.
• MRI sialography for stricture; avoid sialography in acute infection.

Antibiotics, hydration and sialogogues, with stone removal after infection settles.

• Supportive: oral and IV fluids, warm compresses, gentle massage towards the duct, sour sweets or lemon to stimulate saliva, analgesia (paracetamol 1 g, ibuprofen 400 mg), oral hygiene with chlorhexidine 0.2 percent.
• Pharmacological: amoxicillin clavulanate 625 mg three times daily for 7 to 10 days (children 30 mg/kg/day of amoxicillin in three doses); or flucloxacillin 500 mg to 1 g four times daily with metronidazole 400 mg three times daily; severe: amoxicillin clavulanate 1.2 g IV every 8 hours, or flucloxacillin 1 to 2 g IV every 6 hours with metronidazole 500 mg IV every 8 hours; penicillin allergy: clindamycin 300 to 450 mg four times daily.
• Procedures: transoral stone removal for stones in the anterior duct; sialendoscopy with basket retrieval or laser fragmentation; incision and drainage of abscess; submandibular gland excision for recurrent stones or chronic disease.
• Special groups: pregnancy, amoxicillin clavulanate; children, weight based doses and exclusion of viral causes; diabetes, early drainage and glucose control; elderly, correct dehydration.
• Red flags: floor of mouth swelling with tongue elevation, trismus, drooling, stridor, neck swelling, fever with toxicity, fluctuance.
• Follow-up: review at 48 hours; elective stone removal after 2 to 4 weeks; ENT follow up if recurrent.