Clinical features

In approximately a third of individuals exposed to infection there is no apparent clinical illness despite positive serology. (asymptomatic infection is common in children) (1). Clinical symptoms are much more severe in adults & adolescents than in children (2).

There is an incubation period of 14 to 25 days. A prodrome of non specific symptoms like fever, malaise myalgias, and anorexia may be followed by enlargement of one or both parotid glands, developing over a period of 1 to 3 days.

• older children may complain of tenderness over the parotid gland and occasionally ear ache before actual swelling becomes evident (2)
• the parotid enlargement may displace the ear lobe upwards and obliterate the space between the mandible and the sternomastoid muscle
• the swelling may even impede chewing or pronunciation of words (3)
• other salivary glands, namely the submandibular and sublingual salivary glands, may also become inflamed.
• upon looking in the mouth, the tonsils may be displaced towards the midline.

The swellings settle in 7 to 10 days and there is no specific treatment. Salivary gland swelling is not apparent in about 30% of cases. Other causes of unilateral or bilateral parotitis can be divided into infectious & non infectious causes

• infectious causes - include other viral agents like parainfluenza, coxsackievirus, influenza A, Epstein-Barr virus, adenovirus, and suppurative bacterial infection.
• non infectious causes - include salivary calculi, tumors, sarcoid, and Sjögren’s syndrome, ingestion of starch or thiazides, and iodine sensitivity (2).

Reference

• (1) Department of health 2006. Immunisation against infectious disease - "The Green Book". Chapter 23 – mumps
• (2) Gupta R.K et al. Mumps and the UK epidemic 2005. BMJ. 2005;330(7500):1132–1135
• (3) Senanayake S.N. Mumps: a resurgent disease with protean manifestations. MJA 2008; 189 (8): 456-459