Mumps

• Mumps:

  • Acute, generalised viral infection characterised by bilateral parotid swelling
  • Prior to MMR vaccine mumps was common in children - outbreaks now more common in young adults at university
• Aetiology:

  • Viral infection caused by a paramyxovirus (measles is also a type of paramyxovirus)
  • Can infect any organ but the salivary glands are most commonly affected
  • Can affect - testes, ovaries, pancreas and brain
  • Mumps is highly infectious and is spready by respiratory droplets and saliva
  • Incubation period of 16-18 days
  • Transmission rates are highest 1-2 days prior to the onset of symptoms
  • Almost all of those infected subsequently develop life-long immunity
• Clinical features:

  • 15-20% of those infected are asymptomatic
  • Usually a prodrome of non-specific flu like symptoms
  • Parotitis (swelling of parotid glands) - develops in most symptomatic people, usually lasts 3-4 days but can last up to 10
  • Also associated with orchitis and meningitis/encephalitis
• Mumps parotitis:

  • Generally bilateral
  • Causes distortion of the face and neck, giving the distinctive 'hamster face' appearance
  • Skin can be hot and flushed but there is no rash
  • Commonly associated with pain near the angle of the jaw, dry mouth and reduced opening of the mouth
• Investigations:

  • Usually a clinical diagnosis, but confirmation via salivary sample is required as it is a notifiable disease
  • Further investigations required if patients present with meningitis/encephalitis or orchitis to look for other causes
• Management:

  • Self-limiting condition and most children recover within 1-2 weeks
  • Supportive management
  • Admission to hospital if concerns about complications
  • Children should not attend school for 5 days following the development of parotitis
• Complications - orchitis (or epididymo-orchitis):

  • Often occurs without parotitis, but if both are present, orchitis generally develops 4-5 days after the parotitis onset
  • Found in 25% of post-pubertal males with mumps
  • Bilateral in 15-30% of cases
  • Severe testicular pain and tenderness
  • Significant scrotal oedema may make the testes impalpable
  • Bilateral orchitis may lead to subfertility
• Complications - meningitis and encephalitis:

  • Usually occurs without parotitis
  • 15% of people with mumps develop meningism
  • Mumps meningitis is usually mild and self-limiting
  • Mumps encephalitis is rare but can be fatal
• Other complications:

  • Oophoritis - inflammation of the ovaries
  • Deafness - usually unilateral and transient
  • Pancreatitis