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What is Mumps (Parotitis)?
Mumps, also called parotitis, is a contagious viral infection caused by a virus that spreads through saliva and respiratory droplets. The disease is named after its most recognizable feature: painful swelling of the parotid salivary glands, which gives affected individuals a characteristic puffy-cheeked appearance.
Classic Symptoms
The typical initial symptoms of mumps include:
- Fever typically ranges from mild to moderate
- Headache
- Muscle aches
- Fatigue
- Loss of appetite
Only in a second phase does the most characteristic sign appear: swelling of the parotid salivary glands (located just below and in front of the ears), which may affect one or both sides of the face.
Course and Prognosis
Symptoms generally resolve within 7 to 10 days. Serious complications are fortunately rare. Following infection, the individual typically acquires lifelong immunity against the mumps virus. It is worth noting that other viruses can also cause salivary gland swelling. This is why some parents mistakenly believe their child has had mumps more than once.
Treatment and Prevention
There is no specific antiviral treatment for mumps. Management focuses on symptomatic relief and, when necessary, treatment of complications. An effective and mandatory vaccine has been available for decades. It is administered as part of the MMR (Measles-Mumps-Rubella) vaccine, and thanks to widespread immunization, mumps is now rare in countries with high vaccination coverage.
Causes
The causative agent of mumps is the mumps virus, a member of the Paramyxoviridae family (genus Rubulavirus). It is an enveloped, single-stranded RNA virus with a single serotype. This means that infection or vaccination confers long-lasting immunity against all strains.
Pathogenesis
After entering the body through the respiratory tract, the virus:
- Initially replicates in the upper respiratory epithelium and regional lymph nodes.
- Spreads via the bloodstream (viremia) to target organs. The most prominent of these are the parotid salivary glands, where intensive viral replication causes the characteristic inflammation and swelling.
- In some cases, the virus reaches the cerebrospinal fluid (the fluid surrounding and protecting the central nervous system) and can disseminate throughout the body, reaching:
- The brain (causing encephalitis or meningitis).
- The pancreas (causing pancreatitis).
- The testes (causing orchitis in post-pubertal males).
- The ovaries (causing oophoritis in females).
Contagion and Transmission
Mumps is transmitted by the mumps virus present in saliva and respiratory secretions of an infected individual. The routes of transmission include:
- Droplet transmission: An infected person releases virus-laden droplets by coughing, sneezing, talking, or breathing; these droplets are inhaled by nearby individuals
- Contact transmission: An infected person touches their nose or mouth, transferring the virus to their hands, which then contaminates surfaces (door handles, tables, utensils); a susceptible person who touches these surfaces and then touches their own mucous membranes (nose, mouth, eyes) may become infected
- Direct sharing: Sharing cutlery, glasses, plates, or other items with an infected person
Infectious Period
- Infected individuals are contagious from a few days before the appearance of swelling to a few days after
- The virus has been isolated in throat swabs from 2 days before to several days after the onset of parotid swelling
- In individuals with salivary gland involvement, the virus can be detected in saliva from 2–6 days before symptom onset and up to 4 days after
- Importantly, the virus can be spread by individuals who are asymptomatic. These individuals never develop recognizable symptoms but are nonetheless infected and infectious.
Return to School or Work
The patient may return to community settings, such as school or the workplace, once the acute phase has resolved. This typically occurs 5 days after the onset of parotid swelling.
Symptoms
The incubation period (time between exposure and onset of symptoms) ranges from 14 to 25 days, with an average of approximately 17 days.
Prodromal Phase (Before Swelling)
In the days preceding parotid swelling, non-specific prodromal symptoms may appear:
- Mild to moderate fever, which typically lasts 3–4 days
- Muscle aches
- Reduced appetite
- General malaise and headache
Key Symptom: Parotid Swelling
The hallmark of mumps is swelling of one or both parotid glands, which are the large salivary glands located below and in front of the ears along the angle of the jaw. Characteristics include:
- Pain that worsens when eating, speaking, chewing, swallowing, or drinking acidic beverages (such as orange juice or lemonade, which stimulate salivary secretion in inflamed glands)
- Swelling initially visible below the ear, then spreading downward and forward over 1–3 days
- In approximately 1 in 4 cases, only one side is affected (unilateral parotitis)
- In some cases, the submandibular or sublingual salivary glands (under the jaw or tongue) may also be involved, though this is less common
Duration and Variability
- The best-case scenario resolves in 2 days, but the typical duration is up to 10 days
- An estimated 30% of infections are subclinical. In these cases, the individual is infected and contagious but develops no recognizable symptoms.
- Some patients develop only non-specific symptoms without apparent parotid swelling
Differential Diagnosis: Swollen Parotids vs. Swollen Lymph Nodes
Mumps is frequently confused with cervical lymphadenopathy (swollen neck lymph nodes). Key distinguishing features:
- Parotid swelling in mumps is centered at the angle of the jaw, pushes the earlobe upward and outward, and fills the space between the ear and the jaw
- Swollen lymph nodes are more discrete, deeper, and do not typically displace the ear
Diagnosis
The diagnosis of mumps is primarily clinical, based on the characteristic appearance of parotid swelling during medical examination. However, given the dramatic reduction of cases due to vaccination and the possibility of symptom overlap with other conditions, laboratory confirmation is now considered a fundamental public health requirement.
Diagnostic Protocol
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Molecular test (RT-PCR): The gold standard for diagnosis. Performed using a buccal swab, which is obtained by swabbing the mucosa near the opening of the parotid duct (also known as Stensen’s duct), or, less commonly, a urine sample. This test is highly sensitive and specific when performed within the first 3–5 days of parotid swelling.
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Serology: Detection of IgM antibodies in the blood indicates recent infection. However, in vaccinated individuals who nonetheless develop mumps (“breakthrough cases”), IgM may be absent or very weak. In these cases, a fourfold rise in IgG antibody titer between two blood samples taken approximately 2 weeks apart confirms the diagnosis.
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Differential diagnosis: The physician must systematically exclude other causes of parotid swelling, including:
- Viral infections: influenza A, parainfluenza, adenovirus, Epstein-Barr virus (EBV), cytomegalovirus (CMV)
- Bacterial parotitis (suppurative parotitis)
- Salivary gland stones (sialolithiasis)
- Drug-induced parotid swelling
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Further investigations: When neurological symptoms or severe abdominal pain are present, additional workup may include:
- Parotid and pancreatic ultrasound
- Cerebrospinal fluid (CSF) analysis to exclude mumps meningitis
Complications
While most cases of mumps are self-limited and uncomplicated, the virus has the potential to cause serious complications involving multiple organ systems. These are more common in post-pubertal adolescents and adults than in young children.
Neurological Complications
- Meningitis: Inflammation of the membranes surrounding the brain and spinal cord; occurs in up to 10% of cases but is usually self-limited and resolves without permanent sequelae
- Encephalitis: Inflammation of the brain itself; rare but serious
Pancreatic Involvement
Pancreatitis can occur, manifesting with:
Hearing Loss
Approximately 1 in 20 patients may experience temporary hearing impairment. Permanent hearing damage occurs in approximately 1 in 20,000 cases, making it a rare but recognized complication.
In Males
Mumps in adolescent and adult males can lead to orchitis: an inflammation of one or both testicles that approximately affects 1 in 4 males. Orchitis is rare before puberty.
Clinical features of mumps orchitis:
- Typically develops 7–10 days after the onset of parotid swelling
- One testicle (rarely both) becomes swollen, red, hot, and extremely painful
- Accompanied by:
- High fever
- Chills
- Headache
- Nausea and vomiting
- Abdominal pain (which may mimic appendicitis if the right testis is involved)
Pain and swelling typically resolve within 3–7 days, usually concurrent with fever resolution. While unilateral testicular atrophy (shrinkage) can occasionally occur following severe orchitis, infertility remains a relatively rare outcome, particularly when only one testis is involved.
In Females
In approximately 1 in 20 post-pubertal females, mumps can cause oophoritis, which is inflammation of the ovaries. This condition may present with:
- Abdominal and/or pelvic pain
- High fever
- Nausea
Oophoritis rarely causes permanent ovarian damage or infertility, distinguishing it from the orchitis risk in males.
When to Contact a Doctor
Thanks to widespread vaccination, mumps is now rare, but a doctor or pediatrician should be contacted whenever mumps infection is suspected. While the disease is generally not dangerous, its symptoms overlap with other conditions that may require different management, and a confirmed diagnosis is important for public health reporting and contact tracing. It is advisable to call the doctor by telephone first, rather than attending in person, to avoid exposing other potentially unvaccinated patients in waiting rooms.
Emergency: Go to the Emergency Room Immediately If
Because mumps can involve the brain and its membranes, immediate emergency care is needed if the patient develops:
- Stiff neck (nuchal rigidity / torticollis) is a hallmark sign of meningitis.
- Seizures or epileptic fits.
- Lethargy: extreme, abnormal drowsiness.
- Severe headache.
- Altered level of consciousness, including presyncope or syncope (fainting).
Additional warning signs that warrant urgent evaluation:
- Abdominal pain may indicate pancreatitis in both sexes or oophoritis in females.
- High fever with testicular pain and swelling (males) may indicate orchitis, which requires prompt treatment.
Mumps and Pregnancy
Historically, some evidence suggested that mumps during pregnancy might increase the risk of spontaneous miscarriage, particularly in the first trimester. However, current evidence is insufficient to confirm a definitive causal link. As a precaution, pregnant women who are not immune to mumps should avoid close contact with individuals with active mumps infection.
Important: The MMR vaccine is a live attenuated vaccine and is contraindicated during pregnancy. Women who are not immune to mumps should be vaccinated before becoming pregnant, ideally waiting at least 4 weeks after MMR vaccination before conceiving.
Treatment
There is currently no specific antiviral medication effective against the mumps virus. Treatment is entirely symptomatic and supportive while the immune system eradicates the infection. The vast majority of patients recover completely and spontaneously within 1–2 weeks.
Pain and Fever Control
- Paracetamol (acetaminophen) or ibuprofen are the drugs of choice for managing fever and pain in mumps.
- Aspirin must never be given to children or adolescents with mumps (or any other viral infection). There is a risk of Reye’s syndrome, a rare but potentially fatal condition that involves liver and brain damage. This applies to all children and adolescents regardless of age.
Hydration
- Adequate fluid intake is essential to prevent dehydration associated with fever.
- Water and herbal teas are preferable.
- Avoid acidic fruit juices (such as orange juice or lemonade), as acidity stimulates salivary secretion. This can increase pain in inflamed parotid glands.
Local Relief
- Applying cool compresses or ice packs to the swollen parotid area can provide symptomatic relief
- For orchitis: The physician may recommend:
- Complete bed rest
- Use of a scrotal support (jockstrap) to reduce discomfort
- In some cases, a short course of corticosteroids to reduce testicular inflammation
Isolation
To prevent transmission to unvaccinated or susceptible individuals, the patient should:
- Remain at home and avoid close contact with others
- Maintain isolation for at least 5 days from the onset of parotid swelling
Lifestyle and Diet
During the acute phase of illness, chewing can be extremely painful. Dietary modifications are important:
- Soft or semi-liquid foods: Soups, mashed potatoes, yogurt, smoothies made from non-acidic fruits (banana, mango, melon), scrambled eggs, and porridge
- Avoid: Hard, chewy foods; acidic fruits and juices
- Rest: While strict bed rest is not mandatory, intense physical activity should be avoided until symptoms have fully resolved
- Oral hygiene: Gentle but regular oral hygiene helps prevent secondary bacterial superinfection of the irritated glands
Vaccination
Mumps can be effectively prevented through vaccination. The mumps vaccine is not given in isolation but as part of the combined MMR (Measles-Mumps-Rubella) vaccine, which is part of the routine childhood immunization schedule.
Standard Vaccination Schedule
- First dose: Between 12 and 15 months of age
- Second dose: Between 5 and 6 years of age (before school entry)
Two doses of the MMR vaccine provide approximately 88% effectiveness against mumps. While this is not perfect, widespread vaccination has dramatically reduced the incidence of mumps and its complications worldwide.
Who Should Be Vaccinated?
- All children following the routine schedule above
- Unvaccinated adults or those with no evidence of prior immunity, particularly those at higher risk such as university students, healthcare workers, and international travelers, should take extra precautions.
- Note: The MMR vaccine is a live attenuated vaccine and is contraindicated in:
- Pregnant women
- Severely immunocompromised individuals
Always discuss vaccination timing, contraindications, and special circumstances with your pediatrician or family doctor.
Frequently Asked Questions
How can I recognize mumps?
Mumps is typically recognizable by the characteristic swelling of the parotid glands, which are located just below and in front of the ears. This swelling gives the face a distinctive “chipmunk cheek” appearance. The swelling is usually painful and may affect one or both sides. Other symptoms, such as headache, muscle aches, and fever, often appear a few days before the parotid swelling becomes apparent.
How is mumps transmitted?
The mumps virus spreads through direct contact with saliva or respiratory droplets from an infected person. These droplets are released when the person talks, laughs, coughs, or sneezes. The risk of transmission is highest with prolonged close contact and is estimated to occur from 2 days before to 5 days after the onset of symptoms.
Is the mumps vaccine mandatory?
The mumps vaccine is included in the MMR (measles, mumps, and rubella) combination vaccine and is part of routine childhood immunization programs in many countries. Whether vaccination is mandatory or strongly recommended varies by country and jurisdiction.
Can antibiotics treat mumps?
No. Antibiotics are not effective against mumps because it is caused by a viral infection. Antibiotics only work against bacterial infections. Treatment for mumps is symptomatic, focusing on rest, hydration, and fever control. Antibiotics may occasionally be prescribed if a secondary bacterial infection develops as a complication, but they have no effect on the mumps virus itself.
Can you get mumps if you’ve been vaccinated?
Yes, breakthrough infection is possible even in vaccinated individuals, as the MMR vaccine is approximately 88% effective (rather than 100%). However, vaccinated individuals who contract mumps typically experience a milder illness with fewer and less severe complications compared to unvaccinated individuals.
Sources and Bibliography
- CDC: Mumps for Healthcare Providers
- NHS: Mumps (licensed under the Open Government Licence)
- WHO: Mumps
- Hviid A, et al. “Mumps”. The Lancet. 2008;371(9616):932–944.
- Rubin SA, et al. “Recent mumps outbreaks in vaccinated populations”. Journal of Virology. 2012;86(8):4644–4655.
- Mayo Clinic: Mumps
- European Centre for Disease Prevention and Control (ECDC). Mumps: Annual Epidemiological Report 2023.
