What are the causes of parotitis (inflammation of the parotid gland)?

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From the Guidelines

Parotitis is primarily caused by viral infections, with mumps virus being the most common culprit, as evidenced by the fact that mumps is a systemic illness that presents with swelling of 1 or more of the salivary glands, typically the parotid glands 1.

Causes of Parotitis

The causes of parotitis can be categorized into several groups, including:

  • Viral infections: Mumps virus is the most common cause of parotitis, and it can present with swelling of the parotid glands, as well as other symptoms such as fever and respiratory tract infection 1.
  • Bacterial infections: Bacteria such as Staphylococcus aureus and anaerobic bacteria can cause parotitis, particularly in hospitalized patients or those with compromised immunity.
  • Autoimmune conditions: Conditions like Sjögren's syndrome can cause parotitis by triggering an autoimmune response against the salivary glands.
  • Obstructive issues: Salivary stones or ductal strictures can cause parotitis by blocking the flow of saliva and leading to inflammation of the parotid glands.
  • Medications and surgical procedures: Certain medications, such as those that cause dehydration or reduced saliva production, can increase the risk of parotitis, as can surgical procedures that affect the salivary glands.
  • Metabolic conditions: Conditions like diabetes and alcoholism can increase the risk of parotitis due to dehydration and compromised immunity.
  • Radiation therapy: Radiation therapy to the head and neck region can trigger inflammation of the parotid glands and cause parotitis.
  • Poor oral hygiene: Poor oral hygiene can contribute to bacterial parotitis by allowing oral bacteria to ascend into the parotid ducts.

Importance of Accurate Diagnosis

Accurate diagnosis of the cause of parotitis is crucial in guiding appropriate treatment, which can differ significantly between viral, bacterial, and obstructive forms of parotitis. According to a study on the epidemiology of mumps, the virus has been isolated from saliva from 7 days before through 8 days after onset of salivary gland swelling 1, highlighting the importance of prompt diagnosis and treatment. Additionally, a study on the immunization of healthcare personnel notes that mumps is a common cause of parotitis, particularly in unvaccinated or under-vaccinated individuals 1.

From the Research

Causes of Parotitis

The causes of parotitis, which is the inflammation of the parotid gland, can be categorized into viral and bacterial infections.

  • Viral parotitis can be caused by paramyxovirus (mumps), Epstein-Barr virus, coxsackievirus, and influenza A and parainfluenza viruses 2.
  • Bacterial parotitis is generally caused by Staphylococcus aureus, Streptococcus species, and rarely, gram-negative bacteria 2, 3.
  • Anaerobic bacteria, such as Peptostreptococcus species and Bacteroides species, and pigmented Porphyromonas species and Prevotella species, have also been recognized as important causes of parotitis 2, 3.

Predisposing Factors

Certain factors can predispose individuals to suppurative parotitis, including:

  • Dehydration 2, 3
  • Malnutrition 2
  • Oral neoplasms 2
  • Immunosuppression 2
  • Sialolithiasis 2
  • Medications that diminish salivation 2

Other Causes

Other causes of parotitis include:

  • Mumps virus, which is the most common and well-known cause of parotitis 4, 5
  • Mycobacterium tuberculosis and atypical mycobacteria, which are rare causes of parotitis 3
  • Other bacterial pathogens, such as Arachnia, Haemophilus influenzae, Klebsiella pneumoniae, Salmonella spp., Pseudomonas aeruginosa, Treponema pallidum, cat-scratch bacillus, and Eikenella corrodens 3

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Diagnosis and management of parotitis.

Archives of otolaryngology--head & neck surgery, 1992

Research

Acute bacterial suppurative parotitis: microbiology and management.

The Journal of craniofacial surgery, 2003

Research

Parotitis: clinical presentations and management.

Postgraduate medicine, 1982

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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