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MUMPS
Abd El-Salam Dawood MD
Interventional Pediatric Cardiologist
FIBMS-Ped FIBMS-PedCard
Essentials of diagnosis & typical features:
No prior mumps immunization.
Parotid gland swelling.
Aseptic meningitis with or without parotitis.
General Considerations:
Mumps was one of the classic childhood infections; the
virus spread by the respiratory route, attacked almost
all unimmunized children (asymptomatically in 30–
40% of cases), and produced lifelong immunity. The
vaccine is so efficacious that clinical disease is rare in
immunized children. As a result of subclinical
infections or childhood immunization, 95% of adults
are immune. Infected patients can spread the infection
from 1–2 days prior to the onset of symptoms and for
5 additional days.
The incubation period is 14–21 days.
A history of exposure to a child with parotitis is not
proof of mumps exposure. In an adequately
immunized individual, parotitis is usually due to
another cause.
Clinical Findings:
1. Salivary gland disease—Tender swelling of one or
more glands, variable fever, and facial lymphedema
are typical. Parotid involvement is most common; signs
are bilateral in 70% of patients. The ear is displaced
upward and outward; the mandibular angle is
obliterated. Systemic toxicity is usually absent. Parotid
stimulation with sour foods may be quite painful. The
orifice of the Stensen duct may be red and swollen;
yellow secretions may be expressed, but pus is absent.
Parotid swelling dissipates after 1 week.
2.
Meningoencephalitis—prior
to
widespread
immunization, mumps was the "most" common cause
of aseptic meningitis, which is usually manifested by
mild
headache
or asymptomatic
mononuclear
pleocytosis. Fewer than 10% of patients have "clinical"
meningitis or encephalitis. Cerebral symptoms do not
correlate with parotid symptoms, which are absent in
many patients with meningoencephalitis. Although
neck stiffness, nausea, and vomiting can occur,
encephalitic symptoms are rare (1:4000 cases of
mumps); recovery in 3–10 days is the rule.
3. Pancreatitis—Abdominal pain may represent
transient pancreatitis. Because salivary gland disease
may elevate serum amylase, specific markers of
pancreatic function (lipase, amylase isoenzymes) are
required for assessing pancreatic involvement.
4. Orchitis, oophoritis—Involvement of the gonads is
associated with fever, local tenderness, and swelling.
Epididymitis is usually present. Orchitis is unusual in
young children but occurs in up to one third of affected
postpubertal males. Usually it is unilateral and resolves
in 1–2 weeks. Although one third of infected testes
atrophy, bilateral involvement and sterility are rare.
5.
Other—Thyroiditis,
mastitis
(especially
in
adolescent females), arthritis, and presternal edema
(occasionally with dysphagia or hoarseness) may be
seen.
Laboratory findings:
Peripheral blood leukocyte count is usually normal. Up
to 1000 cells/µL (predominantly lymphocytes) may be
present in the CSF, with mildly elevated protein and
normal to slightly decreased glucose. Viral culture of
saliva, throat, urine, or spinal fluid may be positive for
at least 1 week after onset. Paired sera assayed by
ELISA are currently used for diagnosis. Complement-
fixing antibody to the soluble antigen disappears in
several months; its presence in a single specimen thus
indicates recent infection.
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Differential Diagnosis:
Mumps parotitis may resemble the following:
1. Cervical adenitis (the jaw angle may be
obliterated, but the ear does not usually
protrude; the Stensen duct orifice is normal;
leukocytosis and neutrophilia are observed).
2. Bacterial parotitis (pus in the Stensen duct,
toxicity, exquisite tenderness).
3. Recurrent parotitis (idiopathic or associated
with calculi).
4. Tumors or leukemia.
5. Tooth infections.
6. Many viral infections, including parainfluenza,
enteroviruses, EBV, CMV, and influenza virus,
can cause parotitis. Parotid swelling in HIV
infection is less painful and tends to be bilateral
and chronic, but bacterial parotitis occurs in
some children with HIV infection.
Unless parotitis is present, mumps
meningitis
resembles that caused by enteroviruses or early
bacterial infection. An elevated amylase is a useful
clue in this situation.
Isolated pancreatitis is not distinguishable from many
other causes of epigastric pain and vomiting. Mumps
is a classic cause of orchitis, but torsion, bacterial or
chlamydial epididymitis, Mycoplasma infection, other
viral infections, hematomas, hernias, and tumors must
also be considered.
Complications:
The major neurologic complication is nerve deafness
(usually unilateral), which can result in inability to hear
high tones. It may occur without meningitis. Permanent
damage is rare, occurring in less than 0.1% of cases
of mumps. Aqueductal stenosis and hydrocephalus
(especially following congenital infection), myocarditis,
transverse myelitis, and facial paralysis are other rare
complications.
Treatment & Prognosis:
Treatment is supportive and includes provision of fluids,
analgesics, and scrotal support for orchitis. Systemic
steroids have been used for orchitis, but their value is
anecdotal. Surgery is not recommended.