Mumps

Pathophysiology of Mumps

mumps is a:

systemic viral infection caused by paramyxovirus, with characteristic finding of parotid enlargement

Signs and Symptoms

1) prodrome of fever, malaise, and anorexia
2) parotid enlargement (usually bilateral but not always synchronous) 24 hours later
3) swelling of submaxillary and sublingual glands
4) tenderness to palpation at area between earlobe and angle of mandible
5) difficulty talking, chewing, and swallowing
6) orchitis (usually unilateral) with testicular enlargement two to three times normal size (20%)
7) aseptic meningitis with drowsiness, headache, and stiff neck (15%) 8) pancreatitis

Characteristic Test Findings

CSF –

1) increased lymphocytes
2) decreased glucose (this is unusual in viral infections and leads to misdiagnosis of bacterial meningitis)

Histology/Gross Pathology

1) enveloped RNA virus with two major glycoproteins – hemagglutinin-neuraminidase (HN) and fusion (F)
2) red, swollen orifice of Stensen’s duct

Associated Conditions

1) deafness
2) encephalitis
3) transverse myelitis
4) Guillain-Barre syndrome
5) TTP
6) arthritis
7) thyroiditis
8) spontaneous abortions

Inheritance/Epidemiology

1) before vaccine occurred as epidemic disease of young in the USA
2) now > 50% of the 1500 cases/year in USA in young adults
3) also described in epidemics in schools and barracks
4) incubation period is 15 days
5) one attack gives lifelong immunity

Treatment

1) vaccine as part of the MMR (measles-mumps-rubella) vaccine given at 12-15 months of age and 4-6 years of age
2) anecdotal reports of alpha interferon for severe orchitis
3) general supportive care

Tips for USMLE

1) the CSF is atypical for viral meningitis in that the glucose is low (as opposed to a normal level expected in most viral meningitis etiologies)
2) if a 21 year old man has a 2-day history of malaise and low-grade fever; develops swelling in the lower face bilaterally with the right side more pronounced; and who has a red, swollen duct on the inside of his right lateral mouth, think mumps