Mumps is an acute, generalised viral infection characterised by bilateral parotid swelling.1
Prior to the introduction of the measles, mumps, and rubella (MMR) vaccine in 1987, it was common in children, but outbreaks are now more common among young adults at university, especially those who did not receive the MMR vaccine.1
There were over 5000 cases of mumps in England in 2019, more than in any year since 2009.2
Mumps is a viral infection caused by a paramyxovirus, usually affecting children or young adults.1
Although it can infect any organ, the salivary glands are most commonly affected. Less often affected are the testes, ovaries, pancreas, and brain.1
Mumps virus is highly infectious and is spread by respiratory droplets and saliva.3
It has an incubation period of 16 to 18 days, and transmission rates are highest one to two days prior to the onset of symptoms. Almost all of those infected subsequently develop life-long immunity.3
15-20% of those infected with the mumps virus are asymptomatic.3
There is usually a prodrome of non-specific, flu-like symptoms which include fever, headache, malaise, myalgia and anorexia.3
Parotitis (swelling of the parotid glands) then develops in 95% of symptomatic cases and usually lasts three to four days, although can last up to ten.3,1
Mumps is also associated with orchitis and meningitis/encephalitis (see complications section).
Mumps parotitis is generally bilateral. It causes distortion of the face and neck, giving the distinctive ‘hamster face’ appearance (Figure 2).2
The skin can be hot and flushed, but there is no rash. Parotitis is also commonly associated with pain near the angle of the jaw, dry mouth, and reduced opening of the mouth.
High fever with associated neck pain and swelling can be caused by other infections including pharyngitis, tonsillitis, infectious mononucleosis and HIV.1
Parotid stones can also cause pain and swelling but are usually unilateral and occur in older patients. In this case, chewing causes pain as saliva is produced.1
Unilateral testicular swelling and pain can be caused by testicular torsion (although here there are no preceding systemic symptoms, and the testicle has a horizontal lie).1 Bilateral testicular swelling should prompt consideration of epididymo-orchitis caused by sexually transmitted infections.
Meningitis and encephalitis can be caused by other infectious (viral, bacterial, fungal) and non-infectious (neoplastic) agents.6 For more information, see the Geeky Medics guide to meningitis.
Mumps is usually a clinical diagnosis, but confirmation (via a salivary sample) is required as it is a notifiable disease.1
Further investigations are also required if patients present with meningitis/encephalitis or orchitis to look for other causes.
Mumps is a self-limiting condition, and most children recover within one to two weeks.1,3
Supportive management may include simple analgesia (paracetamol and ibuprofen), advice regarding fluid intake and rest.
Admission to hospital is required if there are concerns about complications (e.g. meningitis or encephalitis).3
Children should not attend school for five days following the development of parotitis.3
The MMR (measles, mumps and rubella) vaccination is part of the national immunisation programme. The efficacy of the MMR vaccine (both doses) against mumps is 88%.7
If a person is exposed to mumps and has not been fully immunised, MMR should be offered (in the absence of contraindications).3