On awakening in the morning, a 2-year-old girl was noted to have left-sided facial swelling and was brought to the emergency department. The child had had no fever, trauma to the area, pain, or difficulty in swallowing. Her medical history was unremarkable. Her immunizations were up-to-date; she had received both doses of the measles, mumps, and rubella (MMR) vaccine about 6 months before presentation. There were no sick contacts.
The child had normal vital signs. Other than the soft, nontender, nonerythematous left-sided facial swelling, she had no other abnormalities. Intraoral findings were normal.
Serum amylase levels were elevated, which confirmed the clinical diagnosis of acute parotiditis—swelling and inflammation of one or both parotid glands.1 Acute parotiditis in children most often has a viral origin. Mumps virus is the most common cause of parotiditis and should always be considered in children regardless of immunization status. Mumps (or epidemic parotiditis) is asymptomatic in about one-third of patients. In symptomatic patients, the swelling of the parotid gland begins posteriorly between the mastoid process and the mandible and then moves downward and forward. It characteristically pushes the earlobe upward and outward. The swelling can develop rapidly, within a few hours, and last for about a week on average. Rarely, the submandibular glands may also be involved. Mumps can also present as orchitis in children and adolescents, although sterility rarely occurs.2
Mumps can be confirmed by isolation of the virus in cell culture, detection of mumps-specific IgM antibody, or a 4-fold rise between acute-phase and convalescent-phase mumps IgG antibody titer. In this child, mumps antibody titers were negative. According to the CDC, MMR-vaccinated children in whom mumps develops can have negative IgM titers.3
Other, nonviral causes of parotiditis include Staphylococcus aureus, nontuberculous Mycobacterium, starch ingestion, salivary duct calculi; drug reactions (eg, phenylbutazone, thiouracil, iodides), and metabolic disorders (diabetes mellitus, cirrhosis, and malnutrition).2
Children with acute parotiditis, without confirmed mumps, should be kept home from school or day care for 9 days from the onset of parotid swelling, similar to the protocol for those with confirmed mumps. Unless there is a known outbreak in the community, the occurrence of acute parotiditis without confirmation of mumps does not have to be reported to the CDC. Children with mumps who have not received the MMR vaccine can be vaccinated to prevent future infection.3,4