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

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Last updated: March 6, 2025View editorial policy

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From the Guidelines

Parotitis is primarily caused by viral infections, with mumps virus being the most common cause, as evidenced by the significant decline in mumps cases following the introduction of the mumps vaccine 1. The causes of parotitis can be multifactorial, including:

  • Viral infections, such as mumps, which has been largely controlled through vaccination, with a 99% decline in reported cases in the United States after the introduction of the Jeryl Lynn strain mumps vaccine in 1967 1
  • Bacterial infections, typically caused by Staphylococcus aureus and anaerobic bacteria
  • Autoimmune conditions, such as Sjögren's syndrome
  • Obstructive issues, including salivary duct stones or strictures
  • Medication side effects
  • Radiation therapy to the head and neck
  • Poor oral hygiene, particularly in dehydrated or elderly patients
  • Metabolic conditions, such as diabetes and alcoholism, which may increase susceptibility to parotitis
  • Trauma to the parotid gland region, which can occasionally trigger inflammation The underlying mechanism of parotitis typically involves salivary stasis and retrograde infection from the oral cavity, with bacteria or viruses traveling up the parotid duct into the gland, causing inflammation, swelling, and pain in the area in front of and below the ear. In hospitalized patients, parotitis often results from dehydration, poor oral care, and medication side effects, highlighting the importance of proper oral hygiene and hydration in preventing parotitis 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

Clinical Presentations

The clinical presentations of parotitis can vary, and knowledge of these presentations is essential for differential diagnosis 4.

  • Mumps virus is the most common cause of parotitis, but other causes need to be distinguished from mumps 4.
  • Parotid salivary gland disorder is the most common presentation in adults, while sublinguitis is more common in children 5.
  • Serous meningitis and pancreatitis can also occur, especially in adults 5.

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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