Parotitis is an inflammation of the main salivary gland, the parotid gland, situated just near the angle of the jaw.
1. The most common cause of parotitis is infection with the mumps virus. Other viruses known to cause parotitis are:
- Influenza, and
2. Parotid swelling, with or without inflammation may also be seen in patients with
Sjögren’s syndrome (30-50 percent) and in sarcoidosis (1-6 percent).
3. Bacterial infections, usually in debilitated patients who are dehydrated.
4. Stones in the parotid duct.
5. Drugs: iodine used in X-ray studies and guanethidine (antihypertensive).
6. Tumours of the parotid gland.
Clinical features and diagnosis
Parotid swelling in mumps is usually seen within 48 hours of the onset of non-specific symptoms, such as mild fever, headache and muscle aches. Not all patients with mumps have symptoms, but of those that do, 95 percent will have parotid swelling, affecting both glands in 80 percent of cases. The parotitis is due to direct viral infection of the gland, and is more often found in children between 2 and 9 years of age. Earache may be present, and the opening of the parotid duct in the mouth may be red and swollen.
The swollen gland causes pain and tenderness, and the diagnosis is usually fairly obvious. Underlying contributory causes are usually found on examination - for instance, stones in the duct, but in some cases special tests may be needed.
Blood tests will show signs of infection, and can measure mumps antibodies, and auto-immune antibodies found in sarcoidosis and Sjögren’s syndrome . Raised serum amylase levels will support the diagnosis of mumps. X-rays and sialograms will demonstrate stones or other problems in the parotid duct.
Symptomatic treatment is always given for pain and inflammation, and ice-packs may help to reduce swelling. Paracetamol is recommended for pain relief in children. Aspirin is avoided because of the risk of Reye's syndrome. Fluids are encouraged. Bacterial parotitis is treated with the appropriate antibiotics. Patients with mumps parotitis should be isolated, as they are highly infectious. This may however, not be very effective, because these patients are infective even before they have obvious parotid swelling.
Viral parotitis usually resolves with no complications. Failure to diagnose and treat bacterial parotitis or ductal stones may result in permanent damage to the gland and duct.
The only effective prevention of mumps parotitis is immunisation against mumps.
(Dr A G Hall)