Sialoadenitis (Salivary Gland Inflammation)

How salivary glands work

You have three pairs of major salivary glands: the parotid glands in front of the ears, the submandibular glands under the jaw, and the sublingual glands under the tongue, plus hundreds of tiny minor glands. Saliva drains through small ducts into the mouth. When flow slows or is blocked, bacteria from the mouth can travel back up the duct and infect the gland.

Types and causes

Acute bacterial sialoadenitis

Usually caused by Staphylococcus aureus, sometimes streptococci or mouth anaerobes. Most often affects the parotid gland (bacterial parotitis). Risk factors:

• dehydration
• older age
• recent surgery, especially under general anesthesia
• medicines that dry the mouth (antihistamines, diuretics, antidepressants)
• poor oral hygiene
• feeding tubes or not eating by mouth
• diabetes and weakened immunity

Obstructive sialoadenitis

Salivary stones (sialoliths) block the duct, mostly in the submandibular gland. Swelling typically appears or worsens at mealtimes, then slowly goes down. Infection can follow.

Viral sialoadenitis

• Mumps: painful swelling of one or both parotids with fever; rare in vaccinated populations
• other viruses: influenza, Epstein-Barr, coxsackie, HIV

Chronic and autoimmune sialoadenitis

• Sjögren's syndrome: recurrent or persistent gland swelling with dry mouth and dry eyes
• IgG4-related disease: firm, enlarged glands
• radiation or radioactive iodine treatment for thyroid cancer
• juvenile recurrent parotitis in children

Symptoms

• sudden painful swelling in front of the ear, over the cheek, or under the jaw
• redness and warmth of the skin over the gland
• pain worse when eating or anticipating food
• pus or a bad taste in the mouth; pressing the gland may push pus out of the duct opening
• fever and chills
• difficulty opening the mouth
• dry mouth

Diagnosis

• Examination: swelling, tenderness and pus at the duct opening (inside the cheek opposite the upper molars for the parotid, or under the tongue for the submandibular)
• Pus culture to guide antibiotics
• Ultrasound: detects stones, abscesses and gland changes
• CT scan: for deep infections or abscess
• Blood tests for infection, mumps, autoimmune markers
• Sialendoscopy: a tiny camera into the duct to find and remove stones or narrowing

Treatment

Home care

• drink plenty of fluids
• warm compresses on the swollen gland several times a day
• massage the gland from back to front toward the duct opening
• sialogogues: sour candies, lemon drops or sugar-free gum to boost saliva flow
• good oral hygiene: brushing, flossing, salt-water rinses
• pain relief: acetaminophen (paracetamol) or ibuprofen, following the label dose

Medical treatment

• antibiotics covering Staph aureus for bacterial infection, by mouth for mild cases or intravenously in hospital for severe cases
• drainage of an abscess
• removal of stones by sialendoscopy, through the mouth, or with lithotripsy
• steroids in some autoimmune causes

Recurrent or chronic cases

• sialendoscopy to dilate narrowed ducts and wash out the gland
• surgical removal of the gland (submandibular gland excision or parotidectomy) for repeated infections not controlled otherwise

Complications

• abscess formation
• spread of infection into the neck
• chronic or recurrent infection
• facial nerve injury is a rare risk of parotid surgery

Prevention

• stay well hydrated, especially if older or unwell
• maintain good oral hygiene
• review medicines that cause dry mouth with your doctor
• MMR vaccination prevents mumps

Frequently asked questions

What is sialoadenitis?

Sialoadenitis is inflammation or infection of a salivary gland, usually the parotid gland in front of the ear or the submandibular gland under the jaw. It causes painful swelling, often with fever and a bad taste in the mouth.

What causes a salivary gland infection?

Most infections happen when saliva flow slows from dehydration, medicines, illness or a blocking stone, allowing mouth bacteria to enter the gland. Viruses such as mumps and conditions like Sjögren's syndrome can also cause inflammation.

How do you treat a swollen salivary gland at home?

Drink plenty of water, use warm compresses, massage the gland toward its opening, suck on sour candies to increase saliva and keep your mouth clean. See a doctor if there is fever, pus or no improvement within a day or two, as antibiotics may be needed.

How long does sialoadenitis last?

Acute bacterial sialoadenitis usually improves within 2 to 3 days of starting antibiotics and resolves within about a week. Chronic or stone-related sialoadenitis can recur until the cause is treated.

Is sialoadenitis serious?

Usually not, if treated promptly. Rarely it can form an abscess or spread into the neck. Seek urgent care for spreading swelling, difficulty breathing or swallowing, or high fever.