Types and Causes of Sialadenitis
- Sialadenitis can be acute or chronic, with acute sialadenitis presenting as a red, painful swelling and chronic sialadenitis as recurrent swellings.
- Other types of sialadenitis include autoimmune sialadenitis (e.g., Sjögren's syndrome) and infective sialadenitis (e.g., mumps).
- Sialadenitis can be caused by cancer, autoimmune conditions, viral and bacterial infections, idiopathic causes, or salivary stones.
- Viral pathogens, such as mumps, are more common causes of sialadenitis compared to bacterial pathogens.
- Autoimmune conditions like Sjögren's syndrome and sarcoidosis are often associated with chronic sialadenitis.
- Salivary calculi (stones) are a significant indicator for submandibular gland removal in the absence of neoplasia.

Signs and Symptoms of Sialadenitis
- Sialadenitis causes swelling and inflammation of the major salivary glands.
- Acute sialadenitis is characterised by painful swelling, purulent discharge, and systemic manifestations.
- Chronic sialadenitis presents as intermittent, recurrent tender swellings.
- Autoimmune sialadenitis is usually painless unless there is a secondary infection.
- Mumps, a viral infection, causes bilateral swelling of the parotid glands.

Complications and Histopathology of Sialadenitis
- Abscess formation is a potential complication, with infection spreading along the neck's fascial planes.
- Dental decay is a long-term complication, as decreased saliva production increases the risk of acid erosion.
- Postparotidectomy complications may include facial deformity or facial nerve palsy, which can be temporary or permanent.
- The occurrence of seroma, hematoma, or significant infection should be less than 5%.
- Ludwig angina can result from the spread of infection to the spaces in the floor of the mouth.
- Acute bacterial sialadenitis involves the accumulation of bacteria, neutrophils, and fluid in the ductal structures.
- Chronic sialadenitis is characterised by periductal lymph follicles and further destruction of salivary acini.
- In infective sialadenitis, the lobular architecture of the gland is maintained or slightly expanded.
- Acinar destruction with neutrophil infiltrates is observed in acute bacterial sialadenitis, while vacuolar changes and lymphocytic infiltrate are seen in viral sialadenitis.

Diagnosis and Diagnostic Factors of Sialadenitis
- Consider history, signs and symptoms, and investigations for diagnosis.
- Episodic swelling during meal times, use of xerostomic medications, recent surgical intervention under general anaesthetic, dry eyes and mouth, and oral candidiasis are important diagnostic factors.
- Mandibular trismus, respiratory distress, cranial nerve palsy, connective tissue disorder or Sjögrens syndrome, and recurrent painless swellings are less common diagnostic factors.
- Diagnostic tests may include culture and sensitivity testing of exudate from salivary duct, full blood count, facial radiographs, and other tests as necessary for specific cases.

Treatment and Epidemiology of Sialadenitis
- Conservative therapies for chronic recurrent sialadenitis or chronic sclerosing sialadenitis.
- Empirical antibiotic therapy for infection.
- Surgical excision of the affected gland for severe or frequent attacks.
- Hydration, analgesics, sialogogues, and gland massage for acute attacks.
- Parotid gland sialadenitis is more common than submandibular gland sialadenitis.
- Chronic sialadenitis is relatively common, while bacterial sialadenitis and sclerosing polycystic sialadenitis are rare.
- Chronic sclerosing sialadenitis predominantly affects males over the age of 50.
- Incidence of admissions for sialadenitis is 27.5 per million of the population in the UK.
- Factors such as debilitation, dehydration, and older age may increase the risk of sialadenitis.