Parotid swelling differentials

Mumps

• Viral respiratory droplet infection
• Usually self limiting that lasts for a week
• Initial period of prodrome:
  • Fever
  • Muscle aches
  • Lethargy
  • Reduced appetite
  • Headache
  • Dry mouth
• Then after that parotid swelling - either unilateral or bilateral. WITH PAIN is a key feature so should consider mumps
• May be other symptoms: abdominal pain (pancreatitis), testicular pain (orchitis), confusion, neck stiffness and headache (meningitis or encephalitis)

Other viral

• Herpes
• HIV
• EBV
• COVID-19

Sialolithiasis

• Hardened calculi that form in the gland
• Medication (diuretics, anti-cholinergics or anti-depressants), dehydrations, gout, smoking, hyperparathyroidism
• Usually asymptomatic with intermittent facial swelling associated with eating
• Halitosis 

Sjogren's syndrome

• Autoimmune decrease saliva production → dry mouth
• Fatigue muscle aches 
• Systemic symptoms of gland dysfunction