Parotid gland
Mumps is seen to be a common cause of parotid gland swelling - 85% of cases occur in children younger than 15 years. The disease is highly contagious and spreads by airborne droplets from salivary, nasal, and urinary secretions. Symptoms include oedema in the area, trismus as well as otalgia. The lesion tends to begin on one side of the face and eventually becomes bilateral. The transmission of the paramyxovirus is by contact with the infected persons saliva. Initial symptoms tend to be a headache and fever. Mumps is not fatal, however further complications can include swelling of the ovaries or the testes. Diagnosis of mumps is confirmed through viral serology, management of the condition includes hydration and good oral hygiene of the patient requiring excellent motivation. However, since the development of the mumps vaccine, given at the age of between 4–6 years, the incidence of this viral infection has greatly reduced. This vaccine has reduced the incidence by 99%.
Sialadenitis
Viral pathogens more commonly cause sialadenitis in comparison to bacterial pathogens. Mumps is the most common virus that affects the parotid and submandibular glands, with the parotid gland affected most often out of these two. Other viruses that have been shown to cause sialadenitis in both these glands include HIV, coxsackie and parainfluenza. Classically, HIV parotitis is either asymptomatic or a non-painful swelling, which is not characteristic of sialadenitis. Some common bacterial causes are S. Aureus, S. Pyogenus, S. Viridans and H. Influenzae.