The key in diagnostics is whether the symptom or finding is present in one or more glands.
Unilateral swelling of the submandibular gland is usually due to sialolithiasis.
When the gland is mildly swollen and clear saliva (not pus) comes out of the duct, sufficient treatment usually consists of "milking" (i.e. gently massaging) the gland, adequate drinking and a course of NSAID medication.
Investigations in specialized care are not required after a single episode of inflammation that heals well.
Bilateral swelling with few symptoms may be caused by sialadenosis, which is associated with systemic illnesses, or by Sjögren's syndrome.
A tumour does not manifest itself as a swelling of the entire gland, but usually as an asymptomatic lump.
If unilateral swelling develops gradually, the possibility of a tumour should be considered, particularly in patients over 50 years of age.
In children and adolescents, the aetiology of submandibular gland swelling may be juveline recurrent parotitis (JRP).
Examination of the salivary glands
The starting point for diagnostics is to determine whether the disease is present in one or more salivary glands (picture F1).
The patient's age and gender are also taken into account.
Children and adolescents: viral infections and recurrent juvenile parotitis
Adult patients: salivary calculi, acute or chronic inflammation/infection and tumours
The incidence of rheumatic diseases that may affect the salivary glands is higher in women than in men.
Examination of the submandibular gland includes a bimanual palpation where one hand of the examiner is placed into the patient's mouth and the other under the mandible. Note that healthy parotid glands are usually not easily palpated. Tender gland usually suggests inflammation.
Differential diagnosis of salivary gland swelling
Acute purulent sialadenitis
Painful, unilateral swelling of the gland
Only in severe inflammation, there may there be redness and general symptoms.
The most common causative agents are Staphylococcus aureus, streptococci and Haemophilus influenzae.
Diagnosis
It may be possible to express purulent discharge from the gland. It is advisable to send a sample from the discharge for bacterial culture.
In a mild disease, no laboratory examinations are required. An infection with severe symptoms presents with leucocytosis and an increased CRP concentration.
Treatment
When there are clear signs of inflammation in the gland and/or the duct leaks pus, peroral amoxicillin-clavulanic acid or cephalosporin is used. Duration of treatment altogether is 7-10 days.
If the patient has severe symptoms, the treatment initially consists of intravenous medication, e.g. cefuroxime 750 mg - 1.5 g three times daily for a few days. A drug against anaerobic organisms is often added to the treatment (metronidazole initially intravenously and then 400 mg 3 times daily orally).
If no secretion comes out of the duct spontaneously or by pressing on the gland, a probe should be used to ensure that the duct of the gland is open.
An NSAID drug as a course of is part of the treatment and not just pain management.
Adequate fluid intake (dehydration may be a contributing factor)
Gentle pressure is applied to the gland to help empty it of purulent discharge.
Verify that purulent discharge can exit from the salivary duct. If needed, probing is performed.
Chronic sialadenitis
The inflammations may recur. The gland may become hard and often remains swollen between the periods of acute inflammation.
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 and/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 can 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, as necessary
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 is sometimes performed. Small (< 5 mm) calculi that are suitably situated can be removed endoscopically.
Large stones (> 5 mm) inside the submandibular gland often necessitate the removal of the gland.
If the gland is swollen and the duct does not leak pus, sufficient treatment usually consists of milking the gland, drinking enough and taking NSAID medication as a course. When the duct leaks pus, an antimicrobial drug should be added to the treatment.
Sialadenosis (sialosis)
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.
An alarming finding is the attachment of a solid mass to the surrounding tissues and/or nerve dysfunction (facial nerve or hypoglossal nerve) associated with a salivary gland change.
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 change may also occur behind the angle of the mandible.
If a tumour is suspected, ultrasonography and fine-needle aspiration biopsy can be performed, but regardless of the result the patient must be referred to an otorhinolaryngological clinic for an assessment.
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 by 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.
Referral to specialized care
When do I treat the patient / wait?
Treatable with oral medicines
If symptoms persist or there are previous symptoms, an ultrasound examination should be ordered before consultation.
Emergency referral
General symptoms
Suspected abscess
Severe symptoms; you suspect pus but the excretory duct is blocked and you cannot open it with a probe.
Sialolithiasis; prior ultrasound examination (assessment of whether there is one or more calculi)
Recurrent swelling disturbing the patient (sialendoscopy when symptoms > 3 months)
References
Moore J, Simpson MTW, Cohen N, et al. Approach to sialadenitis. Can Fam Physician 2023;69(8):531-536 [PubMed]
Badash I, Raskin J, Pei M, et al. Contemporary Review of Submandibular Gland Sialolithiasis and Surgical Management Options. Cureus 2022;14(8):e28147 [PubMed]
Wilson KF, Meier JD, Ward PD. Salivary gland disorders. Am Fam Physician 2014;89(11):882-8 [PubMed]
Saarinen R, Kolho KL, Davidkin I, et al. The clinical picture of juvenile parotitis in a prospective setup. Acta Paediatr 2013;102(2):177-81 [PubMed]