The Salivary Glands
Your salivary glands produce saliva, which helps digest food, keeps your mouth moist, and protects your teeth. There are three major pairs of salivary glands: the parotid glands (in front of the ears), the submandibular glands (under the jaw), and the sublingual glands (under the tongue). Sialadenitis is an inflammation of one or more of these salivary glands. It can be caused by infections (bacterial or viral), blockages such as salivary stones, or other underlying conditions. The condition can affect one or both sides of the face and may cause swelling, pain, and difficulty swallowing or opening the mouth.
Understanding Sialadenitis
Sialadenitis can cause a range of symptoms depending on whether it develops suddenly (acute) or persists or recurs over time (chronic). In both cases, the symptoms arise because the salivary gland becomes inflamed, often due to infection or blockage.
Acute Sialadenitis
Symptoms usually appear quickly and are often more intense:
- Sudden swelling of the affected gland (commonly the parotid or submandibular gland)
- Pain and tenderness, which may worsen when eating or at mealtimes
- Redness or warmth over the swollen area
- Dry mouth or reduced saliva flow
- Bad taste in the mouth, sometimes with pus draining into the mouth
- Fever or feeling generally unwell, especially if there is a bacterial infection
- Difficulty opening the mouth (trismus) in more severe cases
Chronic Sialadenitis
Symptoms tend to be milder but may come and go:
- Intermittent swelling, often triggered by eating
- A feeling of fullness or discomfort in the affected gland
- Recurrent pain, sometimes relieved when swelling subsides
- Reduced saliva flow or a dry mouth sensation
- Repeated episodes of inflammation, often linked to partial blockage from a stone or duct narrowing
Common Causes
Sialadenitis occurs when a salivary gland becomes inflamed, usually because something is affecting the normal flow of saliva. This can happen suddenly (acute) or develop gradually over time (chronic).
- Salivary gland stones (sialolithiasis) The most common cause. A small stone can block the duct, causing saliva to back up into the gland and trigger inflammation or infection.
- Bacterial infection Often caused by Staphylococcus aureus and can occur when saliva flow is reduced. Bacteria enter and multiply within the gland, leading to swelling, redness, and pain.
- Viral infection Certain viruses, such as mumps, influenza, and Coxsackie virus, can inflame the salivary glands.
- Reduced saliva flow When saliva is not produced normally, it becomes easier for bacteria to grow and for the duct to become blocked. Causes include dehydration, medications, and autoimmune conditions.
- Autoimmune conditions Conditions such as Sjögren’s syndrome can cause long-term inflammation and reduced saliva production, increasing the risk of chronic sialadenitis.
- Duct narrowing or scarring Previous infections, trauma, or surgery may cause the salivary duct to narrow, affecting saliva flow.
Diagnosing Sialadenitis
Diagnosing sialadenitis involves assessing your symptoms, checking the affected gland, and using imaging if needed to confirm the cause, particularly to look for stones, blockages, or infection. A clinician will examine the swollen gland, checking for tenderness, firmness, or any lumps, and may gently press on the duct inside your mouth to see if saliva flows normally or if pus is present. They’ll also ask about your medical history, including recent infections, dehydration, medications, dry mouth symptoms, or any previous salivary gland stones, as these can help identify the underlying cause.
- Ultrasound An ultrasound scan is usually the first-line, non-invasive test used to assess salivary gland swelling. It can detect salivary stones, duct dilation or blockage, abscesses, and signs of inflammation or structural change within the gland. Ultrasound also helps differentiate between an acute infection, chronic inflammation, and other potential causes of swelling, guiding appropriate management.
- CT or MRI These are not usually needed but may be recommended if symptoms are severe, recurrent, or if a tumour or deep abscess needs to be ruled out.
Treatment Options
Management of sialadenitis depends on the underlying cause, how severe the symptoms are, and whether the condition is acute or chronic. Many cases improve with simple measures, while others may require medical or procedural treatment.
- Supportive measures - Warm compresses applied to the affected gland to ease discomfort and encourage saliva flow., Massage of the gland, gently pushing saliva forward toward the duct opening., Staying well hydrated, which helps thin saliva and reduce blockage., Sucking on sour sweets (like lemon drops) to stimulate saliva production., Good oral hygiene, including regular toothbrushing and mouth rinses.
- Medical treatment - Antibiotics may be prescribed for bacterial infection, especially when fever, pus, or significant tenderness is present., Anti-inflammatory medications (e.g., ibuprofen) may help reduce pain and swelling., Treatment for underlying conditions such as dry mouth (xerostomia), autoimmune conditions (e.g., Sjögren’s syndrome), or medication-induced dryness.
Management for salivary gland stones
When stones (sialoliths) are the cause:
Manual expression by a clinician may remove small stones near the duct opening.
Minimally invasive procedures, such as sialendoscopy, can retrieve deeper stones or break them up.
Lithotripsy (shockwave treatment) may be used in specialist centres for larger stones.
Surgery is rarely required but may be considered if stones are large, recurrent, or unreachable by other techniques.
When chronic sialadenitis requires further treatment
For long-standing swelling, repeated infections, or significant gland damage:
Sialendoscopy can also be used to flush the duct, relieve narrowing, or improve drainage.
Steroid therapy (oral or duct irrigation) may sometimes be used in chronic inflammatory cases.
Surgical removal of the gland (rare) may be considered if symptoms are persistent and significantly affecting quality of life.