Unilateral swelling of the submandibular gland is usually due to sialolithiasis.
Bilateral swelling with few symptoms may be caused by sialadenosis, which is associated with systemic illnesses, or by Sjögren's syndrome.
Investigations in specialized care are not required after an isolated infection that heals without complications.
If unilateral swelling develops gradually, the possibility of a tumour should be considered, particularly in patients over 50 years of age. A tumour usually manifests itself as a lump.
In children and adolescents, the aetiology of submandibular gland swelling may be juveline recurrent parotitis (JRP).
Antimicrobial treatment is necessary if the swelling of the salivary gland is associated with purulent discharge at the orifice of the gland duct or there are other signs of bacterial infection.
Examination of the salivary glands
On symptom emergence, the patient's age and gender must be considered.
Children and adolescents: viral infections and recurrent juvenile parotitis
Middle-aged patients: salivary calculi, acute or chronic infection and tumours
The older the patient, the higher the likelihood of a tumour
The incidence of rheumatic diseases that may affect the salivary glands is higher in women than in men.
The examination includes a bimanual palpation where one hand of the examiner is placed into the patient's mouth. Note that healthy parotid glands are usually not easily palpated, whereas pain on palpation usually suggests inflammation.
Differential diagnosis of salivary gland swelling
Acute purulent sialadenitis
Painful, unilateral swelling of the gland. In severe inflammation, the overlying skin may be red, and the patient may have systemic symptoms.
Only one gland is usually affected.
The most common causative agents are staphylococci and streptococci.
Diagnosis
It may be possible to express purulent discharge from the gland. Any discharge should be sent for bacterial culture.
An infection with severe symptoms presents with leucocytosis and an increased CRP concentration. In a mild disease no laboratory tests are required.
Treatment
If the patient has severe symptoms, the treatment consists of intravenous medication, e.g. cefuroxime 750 mg - 1.5 g three times daily for a few days. Treatment against anaerobic organisms is often also needed (metronidazole initially intravenously and then 400 mg 3 times daily orally). Duration of treatment altogether 7-10 days.
Gentle pressure may be applied in order to empty the gland of purulent discharge.
Verify that purulent discharge can exit from the salivary duct. If needed, probing is performed.
Chronic sialadenitis
The infections may recur. The gland may become hard and often remains swollen between the periods of acute infection.
Requires specialist intervention.
Sialolithiasis is often the underlying cause, particularly when the submandibular gland is affected.
Diagnosis
Clinical examination and ultrasonography
Treatment
The treatment of an acute phase should follow the guidelines given above.
When the submandibular gland is affected the first-line treatment is sialendoscopy and the associated therapeutic interventions. Sialendoscopy is performed if the patient has recurring or long-lasting (> 3 months) symptoms or if a salivary stone is detected. In some cases, excision of the gland during a non-acute phase is indicated.
In chronic sialadenitis of the parotid gland, sialendoscopy may be performed and long term antimicrobial treatment (amoxicillin or doxycycline for 1-2 months) considered.
Other treatment forms are chosen according to aetiology.
Other viral infections may occasionally have similar clinical presentation.
May be unilateral or bilateral.
Sialolithiasis (calculi in the salivary ducts or glands)
The calculi are unilateral and usually develop in the duct of a submandibular gland or, less frequently, the parotid gland.
Pain and swelling occurs after eating. The swelling of the gland or duct develops rapidly, and may last from a few hours to several days.
Diagnosis
Characteristic history
It may be possible to palpate the calculus in the duct.
Ultrasonography, if indicated
Treatment
If the calculi are not removed they may cause chronic sialadenitis. The calculi are removed by dilating and opening the duct either at an otorhinolaryngological or oral clinic. Endoscopic removal may sometimes be used. Small calculi that are suitably situated can be removed endoscopically.
Large stones inside the submandibular gland often necessitate the removal of the gland.
Bilateral, diffuse, slowly progressing painless swelling, usually of the parotid glands. The enlargement of the glands is usually considered to be neuropathic in origin.
The condition is due to changes in the parenchyma of the salivary gland, and not something caused by salivary duct stenosis.
The most common illnesses or conditions associated with sialadenosis are diabetes, alcoholism, liver disease, anorexia and bulimia.
Whenever possible, treatment should target the underlying disease.
Obesity and Sjögren's syndrome may also be associated with a similar enlargement of the salivary glands, but the aetiology differs.
Sjögrens'syndrome
Symptoms include dry mouth Dryness of the Mouth and eyes, often enlarged salivary glands as well as other symptoms.
Usually diagnosed after the age of 40 in female patients.
May be a primary disease or secondary to other connective tissue disease.
First line investigations include the verification of the dryness of the mouth and eyes and testing for SS-A and SS-B antibodies.
A patient with only mouth and eye symptoms can be managed with symptomatic treatment.
Tumours of the salivary glands
A tumour usually presents as a painless and minimally symptomatic lump.
Unilateral occurrence, clear demarcation and usually a solid feel on palpation are characteristic of the lesion.
The lump may sometimes mimic a swollen gland.
Intermittent swelling is very rarely associated with a tumour.
The swelling may also occur behind the angle of the mandible.
If a tumour is suspected, open biopsy must not be carried out. Ultrasonography and fine-needle aspiration biopsy may be performed, but the patient must be referred for a specialist assessment regardless of the result.
Approximately 80% of the tumours are located in the parotid gland, and 80% of these are benign.
Tumours of the submandibular gland are rare. One third of these are malignant.
Juvenile recurrent parotitis (JRP)
Recurring inflammations of the parotid gland, which resolve spontaneously over puberty
The diagnosis is clinical. Aetiology is unknown.
In differential diagnostics, e.g. mandibular causes should be considered.
Consultation within specialized health care is not required after a single parotitis, unless the patient has symptoms.
An ultrasonography is performed at a non-active phase, if the symptoms continue or recur. After a single swelling period an investigation is not required if the clinical status is normal and the patient has no symptoms.
Sialendoscopy is carried out only if the symptoms are prolonged or recur.