You may have recently heard about an outbreak of mumps in the National Hockey League but after seeing several cases of unilateral facial swelling over the angle of the mandible in a school age child you’re probably wondering what’s going on at your home institution as well. Has the MMR vaccine failed? Is everyone suddenly worshipping at the church of Jenny McCarthy? Let’s go ahead and take a close look at viral parotitis shall we?
What is it?
Unsurprisingly, parotitis is an acute infection of the parotid glands. The cause is usually viral, including mumps, influenza, parainfluenza, coxsackie A, echovirus, and HIV. Interestingly, children with HIV with often have chronic parotitis. It is most commonly seen in children <15 years old and presents with unilateral or bilateral parotid swelling following a prodrome of fever, malaise, headaches, myalgias and arthralgias. You know, like the flu. In general patients are thought to be contagious for 7-10 days after the onset of parotid swelling. On exam you’ll note a mildly tender, firm indurated area of swelling extending from the preauricular area that extends below and behind the ear. The angle of the jaw can appear to be blunted. Patients may describe more pain when eating, especially adjacent to the pinna. Involvement of the sublingual and submandibular glands can be seen, but it is much less common. The swelling and symptoms can last for 7-10 days, with the worst being in the first third of illness.
Viral parotitis must be differentiated from acute suppurative parotitis which is most often due to S. aureus. The history includes rapid gland enlargement and severe pain. Patients are also ill appearing with high fevers and toxic appearance. This ill-appearance will persist after defervescence. On physical exam you’ll see erythema and exquisite tenderness. By massaging the gland you may express pus from Stensen’s duct – which is located adjacent to the first upper molar on the buccal surface.
There are noninfectious causes – but these are much less likely in children. They include a sailcloth (a stone blocking the duct), cancers, and traumatic insufflation of the gland (trumpet blowing). Interestingly, cases of mumps will be associated with unilateral orchitis in 20-30% of male patients. Non-parotitis causes of parotid swelling include cystic hygroma, hemangioma, lymphadenitis, parotitis, Sjogren’s and Caffey-Silverman syndrome and lymphoma.
What should I do?
If you suspect suppurative parotitis start antibiotics with appropriate Staph coverage. If levels of MRSA are high in your community choose a drug like Clindamycin. Otherwise, the treatment is supportive, and includes fluids, antipyretics and analgesics. Educate the patient/parent to return for worsening symptoms or pain. Antibiotics are not required for the vast majority of cases, especially if the exam and history are reassuring.
Do I need to send mumps titers?
In short no. Mumps titers, or labs in general are unnecessary unless the child is unimmunized, you have definitive exposure to mumps, or they are immunosuppressed. Though an amylase level can help confirm, the lab is relatively non-specific – so it’s not recommended in the majority of cases. Since influenza is a cause, it would stand to reason that a rise in the number of cases in parotitis may be seen following flu epidemics. See this brief report from Canada and this report from the Journal of Infectious Diseases (1985, will require some searching).
Do I need imaging?
You can sense a theme here I’m sure. Since cases are diagnosed clinically the answer is no. If the child is ill appearing and has fluctuant consider an ultrasound. Even with a drainable collection ENT should be consulted, as you can do more harm than good (chronic fistulous sinus tracts anyone?) by performing a perfunctory I&D in the ED.
