parotitis

Introduction

Inflammation of the parotid gland.

Etiology

• bilateral
  • viruses
    • Epstein-Barr virus
    • human herpes virus type 6
    • mumps
    • parainfluenza virus type 3
    • coxsackievirus
    • influenza A
    • HIV1 infection (generally painless, asymptomatic)
  • metabolic disorders
    • diabetes mellitus
    • uremia
  • pharmaceutical agents
    • phenylbutazone
    • propylthiouracil
    • iodides
    • heavy metals
• unilateral
  • tumor
  • cyst
  • sialolithiasis
  • suppurative parotitis (Staphylococcus aureus)
    • Staphylococcus aureus including MRSA
    • Streptococcus species
    • gram-negative bacteria (rare)
    • anaerobic bacteria mostly Peptostreptococcus & Bacteroides
      • pigmented Porphyromonas, Prevotella
    • beta-Lactamase-producing organisms common
    • predisposing to suppurative infection
      • dehydration, malnutrition, oral neoplasms, immunosuppression, sialolithiasis, medications that diminish salivation
  • tuberculosis (rare), non-tender lump in gland
  • candidiasis
• disease affecting the salivary glands generally cause chronic parotitis
  • see salivary gland disease
  • chronic parotid swelling
    • sarcoidosis
    • Sjogren's syndrome
    • rheumatoid arthritis
    • systemic lupus erythematosus (SLE)
    • human immunodeficiency virus
    • IgG4 disease
  • cystic fibrosis
• juvenile recurrent parotitis

Epidemiology

• equally likely in males & females
• more common in elderly
• accounts for 0.01 to 0.02% of hospital admissions

Pathology

• parotid duct obstruction (sialolithiasis)
• infection (viral infection or bacterial infection)
• inflammation (Sjogren syndrome, rheumatoid arthritis, SLE, sarcoidosis)
• lymphoepithelial cysts occur in HIV1 parotitis
• noncaseating granulomata are present in sarcoid parotitis
• lymphocytic invasion with acinar destruction can be seen with lymphoma

Clinical manifestations

• bilateral parotid involvement is typical for viral & inflammatory disorder
• unilateral parotid swelling, pain, & fever suggest bacterial cause
• jaw pain aggrevates chewing
• parotid gland enlargement & swelling
• dry mouth
• fever may be noted

* also see Etiology

Laboratory

• gram stain of aspirate if bacterial causes suspected
• culture of aspirate
  • plated on media supportive for growth of aerobic & anaerobic bacteria, mycobacteria, & fungi
  • antimicrobial sensitivity of any cultured growth
• histopathology of incisional or fine needle biopsy
• laboratory values generally elevated, supportive, but nonspecific
  • serum amylase
  • serum C-reactive protein (CRP)
  • erythrocyte sedimentation rate (ESR)

Diagnostic procedures

• sialendoscopy is useful in chronic parotitis & juvenile recurrent parotitis
• incisional or fine-needle biopsy of the parotid tail
  • care to avoid the facial nerve
  • send for culture &/or histopathology

Radiology

• rarely necessary
  • scintigraphy may play a role in diagnosis of chronic obstructive parotitis
• parotid ultrasonography
  • might confirm sialolithiasis
  • can identify abscesses, differentiate between solid & cystic masses & & identify hypoechoic areas seen in punctate sialectasis
• plain radiographs or computed tomography without contrast, can confirm sialolithiasis & multiple parotid calcifications in chronic parotitis
• magnetic resonance imaging (MRI)
  • can differentiate chronic parotitis & neoplastic changes within the parotid
  • can demonstrate multiple cyst formation of HIV1 parotitis
• sialography is the gold standard
  • can provide detailed visualization of the parotid ductal system & acini
  • not commonly performed

Complications

• includes parotid procedures
  • facial nerve palsy
  • osteomyelitis
  • Lemierre syndrome
  • sepsis

Differential diagnosis

• sialadenosis

Management

• symptomatic control
  • local application of heat
  • gentle massage from posterior to anterior
  • sialagogues
  • adequate hydration
  • acetaminophen &/or ibuprofen generally sufficient for pain
• if purulent drainage is expressed during the glandular massage, swab or fine needle aspiration with culture & sensitivity
• empiric therapy is directed against both aerobic & anaerobic bacteria
  • community-acquired parotitis
    • nafcillin, oxacillin or cefazolin (1st line)
      • IV vancomycin or clindamycin for MRSA may be prudent
  • nosocomial parotitis
    • cefoxitin, ertapenem, or ampicillin/sulbactam
    • levofloxacin, clindamycin, or piperacillin-tazobactam as alternatives
  • dental infection parotitis
    • clindamycin or metronidazole (anaerobic coverage) + ceftriaxone
    • piperacillin-tazobactam as an alternative
• surgical drainage may be indicated when pus has formed
  • consult otolaryngology early for incision & drainage for cases of acute parotitis refractory to hydration, sialagogues & antibiotics
• see sialolithiasis for removal of salivary stone
• parotidectomy is usually the last resort for chronic parotitis
• surgery may be necessary for facial nerve paralysis
• treat underlying condition

More general terms

• sialadenitis

Additional terms

• parotid gland