Mumps
Exam Tips
- Classic OSCE clue: parotid swelling with ear lobe lifted and loss of mandibular angle suggests parotitis rather than cervical lymphadenopathy.
- Mumps is a notifiable disease in the UK: notify on suspicion, then arrange oral-fluid testing.
- Infection-control pearl: advise exclusion from school/work for 5 days after parotitis onset.
- Complications can occur without obvious parotitis, especially orchitis or aseptic meningitis.
- Public health viva point: give catch-up MMR to under-immunised contacts; MMR is contraindicated in pregnancy and severe immunosuppression.
- Image recognition: review bilateral parotid swelling and ear-lobe displacement in UKHSA Green Book mumps chapter figures.
Definition
Mumps is an acute systemic viral infection caused by the mumps virus (a paramyxovirus) that classically presents with painful swelling of one or both parotid glands. It spreads via respiratory droplets, saliva, and fomites, has an incubation period typically around 14-18 days (range 12-25), and infectivity is highest from about 1-2 days before to 5 days after parotid swelling begins.
Pathophysiology
After entry via the upper respiratory mucosa, mumps virus replicates locally and then disseminates through viraemia to glandular and neural tissues. Tropism for salivary glands causes interstitial oedema and inflammation (parotitis), while spread to testes/epididymis, ovaries, meninges, pancreas, and rarely myocardium explains extra-salivary disease. Post-pubertal gonadal inflammation can reduce spermatogenesis transiently; bilateral severe orchitis may cause testicular atrophy and subfertility. Immune response is usually protective long term, but reinfection can occur.
Risk Factors
- Incomplete immunisation (fewer than 2 doses of MMR vaccine)
- Close-contact settings (households, schools, universities, military barracks)
- Contact with a case (same room >=15 minutes or face-to-face exposure)
- Outbreak settings in the local area
- Adolescent/young adult age group, especially if under-immunised
- Post-pubertal male sex (for epididymo-orchitis complication risk)
Clinical Features
Symptoms
- Prodrome: low-grade fever, malaise, headache, myalgia, anorexia
- Earache and painful jaw movement/chewing
- Parotid pain and swelling (often starts unilateral, then bilateral)
- Difficulty speaking or chewing during peak gland swelling
- Complication symptoms: severe headache/neck stiffness/vomiting (meningitis), testicular pain/swelling, lower abdominal pain (oophoritis), upper abdominal pain (pancreatitis), hearing change
Signs
- Tender parotid enlargement with loss of mandibular angle
- Ear lobe displaced upward/outward over enlarged gland
- Unilateral or bilateral parotitis (bilateral more typical overall)
- Possible submandibular/sublingual gland swelling
- In epididymo-orchitis: enlarged warm tender testis, erythematous scrotum, systemic fever
Investigations
Management
Lifestyle Modifications
- Notify local Health Protection Team on clinical suspicion (do not wait for lab confirmation)
- Self-isolate from school/work for 5 days after onset of parotid swelling
- Rest, maintain hydration, and use warm/cool compresses over painful salivary glands
- Safety-net: urgent review for severe headache, neck stiffness, reduced consciousness, seizures, severe testicular pain/swelling, or dehydration
- Offer catch-up MMR to under-immunised contacts when clinically well to reduce future risk
Pharmacological Treatment
Analgesic/antipyretic
- Paracetamol adult: 500 mg-1 g orally every 4-6 hours when required (max 4 g/day)
- Paracetamol child: 15 mg/kg per dose every 4-6 hours (max 60 mg/kg/day, usual max 4 doses/24 h)
First-line symptomatic treatment. Check total daily dose from all formulations to avoid hepatotoxicity.
NSAID
- Ibuprofen adult: 200-400 mg orally three times daily with food when required (usual max 1.2 g/day without specialist advice)
- Ibuprofen child >=3 months: 5-10 mg/kg per dose three times daily (max 30 mg/kg/day)
Avoid/caution in dehydration, renal impairment, active GI ulceration/bleeding, NSAID hypersensitivity, and severe asthma sensitive to NSAIDs.
Vaccination (contact/public health management)
- MMR vaccine: 0.5 mL by SC or IM injection per dose, complete 2-dose schedule if not fully immunised
Live vaccine: contraindicated in pregnancy and severe immunosuppression. Not a treatment for current illness but important for future protection and outbreak control.
Not recommended routinely
- Antibiotics
- Corticosteroids
- Human normal immunoglobulin (HNIG)
Do not use for uncomplicated mumps; reserve antibiotics only if clear bacterial co-infection.
Safety warning in children
- Aspirin: avoid in under 16 years
Risk of Reye syndrome.
Complications
- Epididymo-orchitis (commonest in post-pubertal males; may be bilateral, with risk of testicular atrophy/subfertility)
- Aseptic meningitis
- Encephalitis (rare but potentially severe)
- Oophoritis
- Pancreatitis (usually mild)
- Transient sensorineural hearing loss; permanent deafness is rare
- Myocarditis/ECG changes (rare clinically significant disease)
- Rare neurological syndromes (for example cerebellar ataxia, transverse myelitis, Guillain-Barre syndrome)
Prognosis
Most cases are self-limiting and improve within 1-2 weeks with supportive care, with no long-term sequelae. Prognosis is generally excellent, but complications are more frequent in adults than children, and gonadal/CNS involvement requires closer follow-up.
Sources & References
🏥BMJ Best Practice(1)
✅NICE Guidelines(1)
- Mumps[overview]
📖Textbook References(2)
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1505, 1506)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1504, 1505)[context]