Parotitis, Acute and Chronic

BASICS

Definition: Inflammation of the parotid gland (largest salivary gland) due to infection (viral/bacterial/fungal), systemic disease, mechanical obstruction, or medications.
Location: Parotid gland is lateral/anterior to masseter, extends over sternocleidomastoid; Stensen duct opens at buccal mucosa (opposite maxillary second molar).
Facial nerve divides gland into lobes.

Viral parotitis: Most common in children; incidence decreased with mumps vaccine, but increased with SARS-CoV-2.
Bacterial parotitis: Less common; more frequent in elderly, neonates, post-op patients.
Juvenile recurrent parotitis (JRP): Second most common in children; usually presents at ages 3–6.
Chronic parotitis: Primarily adults (40–60 yrs); chronic bilateral parotid enlargement common in HIV.

Viral: Mumps (paramyxovirus, classic, 16–18 days after infection, reportable), parainfluenza, enterovirus, EBV, HHV-6, influenza A, coxsackievirus, SARS-CoV-2.
Bacterial: Salivary stasis → retrograde bacterial invasion; most common—Staph aureus, then Strep pneumoniae, anaerobes; others: E. coli, H. influenzae, Klebsiella, Enterobacter, Pseudomonas (in chronically ill/hospitalized).
Fungal: Candida, Actinomyces (with trauma/dental caries).
Other causes: Sialolithiasis (stones), ductal stenosis, trauma, autoimmune disease (Sjogren), medications, HIV, tuberculosis, sarcoidosis, Kawasaki disease.
Special: Pneumoparotitis (air in duct; wind instrument players, glassblowers, dental procedures), "anesthesia mumps" (transient, post-anesthesia).

Immunosuppression, HIV, chemo, radiation, malnutrition, alcoholism
Acute viral: Lack of MMR vaccination
Acute bacterial: Dehydration, poor oral hygiene, Sjogren, cystic fibrosis, eating disorders, sialolithiasis, duct stenosis, trauma
Neonates: Prematurity, dehydration, low birth weight, duct obstruction, trauma
JRP: Congenital duct malformation, dental malocclusion, immune anomalies
Medications: Anticholinergics, ACE inhibitors, antihistamines, tricyclics, antipsychotics, iodine, L-asparaginase
Chronic: Duct stenosis, HIV, TB, sarcoidosis, uremia, DM, gout, atopy

Acute onset pain/swelling (cheek, parotid region)
Viral: usually bilateral, systemic symptoms (malaise, fever, headache, myalgias, arthralgias)
Bacterial: fever, often unilateral, pain, swelling, sometimes trismus, halitosis
JRP: unilateral, resolves in ~2 weeks
Chronic: recurrent or persistent nontender swelling
Symptoms: Trismus, pain with chewing/salivation, dry mouth, abnormal taste, dehydration
Stones: Recurrent acute swelling/pain, worse with eating

Lymphoma/neoplasm, lymphangitis, cervical adenitis, otitis externa, odontogenic infection, Ludwig angina, cellulitis

Diagnosis usually clinical (history/exam)
Culture: Purulent drainage (aerobic); fine-needle aspiration for anaerobic
Labs: Leukocytosis, elevated amylase (bacterial)
Viral: Mumps—buccal swab for RT-PCR (≤3 days), add IgM (>3 days); repeat if high suspicion
Immunocompromised: CMV titers
Chronic: HIV, PPD, SSA/SSB, ANA, RF
Imaging: Ultrasound (first line, sensitive for abscess/stones), CT/MRI if abscess, mass, or duct issue suspected
Chronic: Sialography (anatomy, functional status)
Biopsy/FNA: If suspicion for TB, sarcoid, Sjogren

Viral: Supportive only. Start antibiotics if toxic-appearing.
Acute bacterial:
Outpatient: Amoxicillin-clavulanate OR ciprofloxacin + clindamycin
Chronically ill/hospitalized: Ampicillin-sulbactam OR cefuroxime + metronidazole; MRSA risk: vancomycin or linezolid
Sjögren's: Pilocarpine/cevimeline (stimulate saliva), botulinum toxin for refractory cases

Sialolithiasis, ductal stenosis, chronic obstruction, >1 recurrence/year (Otolaryngology)
Parotid mass, suspicion of malignancy, nonresponse to antibiotics
Severe/refractory: possible parotidectomy

Mumps: Orchitis, oophoritis, meningitis, pancreatitis, myocarditis, hearing loss, nephritis
Bacterial: Abscess, facial paralysis
Chronic/autoimmune: Neoplasm, facial nerve palsy

Diagnosis: Clinical (swelling/tenderness, ± purulent Stensen duct drainage)
Acute bacterial: S. aureus, S. pneumoniae, anaerobes
Recurrent/chronic: Consider HIV, autoimmune
Most cases: Self-limited, supportive care effective (local heat, massage, hydration)
Prevention: Oral hygiene/hydration in chronically ill/hospitalized can reduce risk