Clinical Subject Page

Mumps

Mumps is an acute, contagious viral infection caused by the mumps virus, a member of the Paramyxoviridae family. It primarily affects the salivary glands, especially the parotid glands, producing painful swelling and fever

Also called

Epidemic parotitis

ICD-10

B26.9

Specialty

Infectious

Onset

Acute

Reviewed

August 2026

On This Page

Overview

Overview
Etiology & Risk Factors

Etiology & Risk Factors
Pathophysiology

Pathophysiology
Clinical Presentation

Clinical Presentation
History Taking

History Taking
Physical Examination

Physical Examination
Investigations

Investigations
Diagnosis

Diagnosis
Management

Management
Complications

Complications
Prognosis

Prognosis
Key Points / Clinical Pearls

Key Points / Clinical Pearls

Overview

–Mumps is transmitted mainly through respiratory droplets and direct contact with infected respiratory secretions. After replication in the respiratory tract, the virus spreads systemically and commonly reaches the salivary glands.

The classic presentation is:

Fever + malaise + painful parotid swelling

Other organs, particularly the testes, central nervous system, and pancreas, may also be affected

Teaching point Painful bilateral or unilateral parotid swelling with fever, especially in an unvaccinated patient or during an outbreak, should raise suspicion for Mumps.

Etiology & Risk Factors

-Etiology

–Mumps is caused by the mumps virus, an enveloped, single-stranded RNA virus belonging to the Paramyxoviridae family.

Transmission occurs through:

Respiratory droplets
Saliva
Close contact with infected individuals

-Risk Factors

Lack of vaccination
Close contact with an infected person
Crowded living conditions
Recent exposure during an outbreak
Immunocompromised state

Pathophysiology

Respiratory exposure → viral replication in the upper respiratory tract → viremia → dissemination to salivary glands and other tissues → inflammation and edema → parotitis ± involvement of testes, pancreas, or central nervous system

Clinical Presentation

-Symptoms:

Mumps commonly causes:

Fever
Headache
Malaise
Myalgia
Loss of appetite
Painful parotid swelling
Ear or jaw pain
Pain while chewing or swallowing

Complicated disease may cause:

Testicular pain and swelling
Severe headache
Neck stiffness
Abdominal pain
Nausea and vomiting

-Signs:

Tender parotid enlargement
Swelling below and in front of the ears
Fever
Erythema around the parotid duct opening in some patients
Orchitis in postpubertal males

Parotid swelling may initially occur on one side and later become bilateral.

-Severe Disease

Severe Mumps may cause:

Orchitis
Meningitis
Encephalitis
Pancreatitis
Sensorineural hearing loss
Oophoritis in females

Important Note Parotid swelling is characteristic but not universal; other causes of parotitis should be considered when the clinical presentation is atypical.

History Taking

-Ask about:

Fever and duration
Onset of facial or parotid swelling
Pain while chewing or swallowing
Headache or neck stiffness
Testicular pain or swelling
Abdominal pain
Vaccination history
Recent contact with a suspected case
Recent travel or outbreak exposure

Physical Examination

-General Examination

Temperature
Hydration status
General appearance
Signs of systemic illness

-System-Specific Examination:

Inspect and palpate the parotid glands
Examine the oral cavity and Stensen duct openings
Assess for cervical swelling
Examine the testes in symptomatic postpubertal males
Perform neurological examination if meningitis or encephalitis is suspected
Assess the abdomen if pancreatitis is suspected

Investigations

Mumps · Investigations & Diagnostic Approach

Suspect clinically

Unvaccinated / incomplete MMR
Contact with confirmed case
Prodrome: fever + malaise + headache (1–2 days)
Parotid swelling — unilateral → bilateral (75%)
Earache aggravated by chewing
Incubation: 16–18 days (range 12–25)

Examine carefully

Parotid enlargement — pushes earlobe upward and outward
Tender, doughy swelling over angle of jaw
Stensen's duct orifice — red, oedematous (pathognomonic)
Trismus — jaw stiffness from parotitis
Check testes (orchitis — males post-puberty)

Confirm — lab tests

Mumps IgM serology — 1st line
RT-PCR — buccal swab / urine — most sensitive
Serum amylase — elevated (parotitis)
Lipase — if pancreatitis suspected
FBC — leukopenia + lymphocytosis

Assess complications

Orchitis: USS testes — exclude torsion
Meningitis: LP if neck stiffness / altered GCS
Pancreatitis: lipase + CT abdomen
Hearing loss: pure tone audiometry
Notify public health — notifiable disease

Investigation Panel

Test	Sample & Timing	Sensitivity	Notes
Mumps IgM	Serum — from day 3–5 of parotid swelling; best at day 5–7	~80% — 1st line	May be falsely negative in vaccinated individuals — IgM response weaker in previously immunised. If negative with high suspicion → send RT-PCR.
Mumps IgG (paired)	Acute (day 0–5) + convalescent (day 14–21) — 4× rise confirms infection	Retrospective	Useful when IgM negative. Single IgG positive = past infection or vaccination — not diagnostic alone.
RT-PCR	Buccal swab (Stensen's duct) + urine — within 5 days of parotid swelling onset; best days 1–3	Highest sensitivity	Gold standard — especially in vaccinated individuals where IgM is unreliable. Identifies genotype for outbreak tracking. Send even if IgM positive.
Serum amylase	Serum — any time during parotitis	Supportive	Elevated from salivary gland origin — not pancreatic. Cannot distinguish parotid vs pancreatic amylase without isoenzyme analysis. Supports clinical diagnosis.
Serum lipase	Serum — if abdominal pain present	Pancreatitis	Lipase more specific for pancreatic involvement than amylase. Elevated lipase + amylase = mumps pancreatitis. CT abdomen if severe.
FBC	Blood	Supportive	Leukopenia + relative lymphocytosis — typical viral pattern. Thrombocytopenia rare. Not diagnostic alone.
LFTs / renal function	Serum	Baseline	Mild LFT elevation in some. Renal function if nephritis suspected (rare).
LP (lumbar puncture)	CSF — if meningism or altered consciousness	Complication screen	Mumps meningitis: lymphocytic pleocytosis, normal glucose (unlike bacterial), elevated protein. Mumps PCR on CSF confirms. Aseptic meningitis in 10% — often subclinical.
USS testes	Scrotum — if orchitis suspected	Complication screen	Orchitis in 20–30% post-pubertal males. USS distinguishes mumps orchitis (hyperaemia, enlargement) from testicular torsion (surgical emergency — absent flow on Doppler).
Pure tone audiometry	Audiology — if hearing loss reported	Complication screen	Sensorineural hearing loss — rare but permanent. Unilateral high-frequency loss. Most common cause of acquired unilateral sensorineural deafness in children.

Differential Diagnosis of Parotid Swelling

Condition	Distinguishing features	Key differentiator
Bacterial parotitis	Unilateral, very tender, hot, erythematous. Pus expressible from Stensen's duct. High fever. Dehydrated/elderly patients. S. aureus most common.	Pus from duct Unilateral only
Parotid calculus (sialolithiasis)	Recurrent swelling — worse with eating. May see stone on plain X-ray or USS. No fever. Colicky pain.	Intermittent, meal-related
HIV parotitis	Bilateral parotid enlargement. Diffuse, non-tender. CD4 count low. Known HIV.	HIV positive
Sjögren's syndrome	Bilateral parotid enlargement. Dry eyes (xerophthalmia) + dry mouth (xerostomia). Autoimmune. Anti-Ro/La antibodies.	Dry eyes + dry mouth
Parotid tumour	Unilateral, painless, firm, slow-growing. Pleomorphic adenoma most common (benign). Facial nerve palsy = malignant.	Painless, no fever
Cervical lymphadenopathy	Nodes below and behind angle of jaw — not over it. Earlobe not displaced. Stensen's duct normal.	Earlobe not displaced
Other viral parotitis	CMV, parainfluenza, influenza A, coxsackievirus — all can cause parotitis. Serology / PCR differentiates.	Serology / PCR

Key exam point — vaccinated patients: Mumps can occur in vaccinated individuals (vaccine effectiveness ~88% after 2 doses). IgM may be negative — always send RT-PCR from buccal swab. Serology alone is insufficient in outbreak settings in vaccinated populations. Mumps is a notifiable disease — report immediately to public health.

Diagnosis

-Mumps is suspected clinically in a patient with:

Acute parotid swelling + fever ± compatible exposure or vaccination history.

-Laboratory confirmation is obtained with RT-PCR from a buccal specimen and/or serological testing when indicated.

The diagnosis should also consider other causes of parotitis.

Home Home Clinical Cases Infectious System Clinical Cases Mumps

Management

1. First-Line / Emergency Management

There is no routine emergency antiviral treatment.

Initial management includes:

Isolation
Adequate hydration
Analgesia
Fever control
Assessment for neurological or testicular complications

Patients with suspected Mumps should avoid close contact with others during the infectious period.

2. Definitive Treatment

There is no specific curative antiviral therapy for uncomplicated Mumps.

Treatment is mainly supportive.

3. Medical Treatment

Paracetamol or NSAIDs for pain and fever when appropriate
Adequate oral fluids
Antiemetics when necessary
Treatment of complications according to the affected organ

Antibiotics are not indicated unless a secondary bacterial infection is present.

4. Supportive Management

Rest
Adequate hydration
Soft foods if chewing is painful
Cold or warm compresses for parotid discomfort
Scrotal support and analgesia for orchitis

Complications

Orchitis
Epididymo-orchitis
Oophoritis
Meningitis
Encephalitis
Pancreatitis
Sensorineural hearing loss
Mastitis
Infertility or impaired fertility in severe orchitis
Rare death

Prognosis

The prognosis of Mumps is generally excellent, with most patients recovering completely with supportive care. Complications are more common in adolescents and adults than in young children. Orchitis can cause testicular atrophy and may impair fertility, particularly when bilateral. Neurological complications and permanent hearing loss are uncommon but potentially serious.

Key Points / Clinical Pearls

Mumps is an acute viral infection caused by the mumps virus.
It spreads mainly through respiratory droplets and saliva.
Lack of vaccination is an important risk factor.
Painful parotid swelling is the classic presentation.
Parotitis may be unilateral or bilateral.
Fever, headache, and malaise commonly precede or accompany parotid swelling.
RT-PCR from a buccal specimen is an important diagnostic test.
Mumps IgM can support the diagnosis but may be negative early.
Treatment is mainly supportive.
Antibiotics have no role unless secondary bacterial infection occurs.
Orchitis is an important complication in postpubertal males.
Mumps can cause meningitis and encephalitis.
Pancreatitis and sensorineural hearing loss can occur.

Centers for Disease Control and Prevention (CDC). Mumps .
Centers for Disease Control and Prevention (CDC). Mumps — Pink Book .
World Health Organization (WHO). Mumps .
Hviid A, Rubin S, Mühlemann K. Mumps. Lancet. 2008;371(9616):932-944. PubMed .
Galazka AM, Robertson SE, Kraigher A. Mumps and Mumps Vaccine: A Global Review. Bull World Health Organ. 1999;77(1):3-14. PubMed .
National Library of Medicine (NIH). Mumps . StatPearls.