The parotid gland is the largest of the sailvary glands lying on either side of the face, towards the back of the jaw and slightly below and in front of the ears. These two glands produce and secrete saliva along with the other salivary glands in the mouth. Like any organ, the parotid gland can become afflicted with a range of diseases and disorders. Swelling of the parotid gland is one such problem that may be encountered.
Why does the parotid gland swell?
A swollen parotid gland may occur due to various different causes. Some of these causative conditions may be mild and temporary whereas others can be serious. Swelling is a consequence of inflammation, fluid or blood accumulation, or abnormal growths. Sometimes this swelling can cause obvious enlargement of the face on the affected side and it may also affect the parotid gland’s normal functions, namely producing and secreting saliva.
Swelling usually refers to fluid accumulation. One of the more common reasons for a swollen parotid gland is inflammation. Here the blood vessels to the gland widen and fluid from the blood seeps into the tissue spaces of the parotid gland. It is triggered by local tissue injury. If the injury is severe or if a blood vessel is damaged then blood may also accumulate in the parotid gland tissue.
Another possible cause of swelling is accumulation of pus known as an abscess. This occurs with an infection. Since the parotid gland produces and secretes saliva, any disruption to the outflow of this saliva can cause it to accumulate within the gland. Lastly an abnormal growth like a benign tumor, cyst or malignancy (cancer) can also cause the parotid gland to appear swollen.
Signs and Symptoms
Swelling of the parotid gland is a symptom and may occur with a number of other symptoms. This includes:
- Lack of saliva in the mouth leading to mouth dryness.
- Excessive saliva production leading to drooling.
- Pain toward the back of the jaw and ear.
- Tenderness over the area where the parotid gland lies.
- Slurred speech may be present in some conditions.
- Diminished taste sensation.
- Excessive thirst often due to dryness of the mouth.
Various other signs and symptoms may also be present depending on the cause of a swollen parotid gland. This may include fever, enlarged lymph nodes, difficulty swallowing and bleeding from the mouth. In some cases there may also be skin redness or a rash over the area where the parotid gland is located.
It is important to note that one-sided facial swelling is not always due to the parotid gland. Injury to the cheek area, enlargement of the cheek muscles like the masseter, fluid accumulation in the face and allergic reactions like hives can cause swelling without involving the parotid gland.
WARNING: Symptoms like unintentional weight loss, bleeding from the mouth and severe pain should be investigated immediately as these may be signs of cancer. Rapid diagnosis and the appropriate treatment will make a significant difference in the prognosis. Always consult with a medical doctor.
Read more on bleeding in the mouth.
Causes of Swollen Parotid Gland
Some of the possible causes of a swollen parotid gland has been discussed below. Inflammation of the parotid gland, whether due to trauma, infection or any other cause, is known as parotitis.
Injury to the parotid gland can through a number of different ways. The injury may be mechanical, chemical or electromagnetic in nature. It may be injured during surgery, with a blow to the face or penetrating force, from toxins and other chemicals or with radiation to the head as part of treatment for cancer. Injury triggers inflammation as the body tries to minimize tissue damage and one of the features of inflammation is tissue swelling.
Infectious agents like viruses and bacteria can also cause inflammation of the parotid gland. Mumps is a common childhood viral infection that causes swelling of the parotid. This is usually not serious and will resolve with proper management as the infection subsides. Bacterial infections of the parotid are more likely to arise with penetrating injuries of the gland while people with HIV and AIDS are prone to repeated infections of the parotid gland.
Read more on mumps.
Any cause of blockage of the salivary duct can cause saliva to accumulate in the parotid gland. One possible cause is the formation of a salivary gland stone, which is also known as sialolithiasis. However, even swelling of the duct can cause it to narrow and eventually become blocked. Similarly tumors may press on the duct and block the outflow of saliva from the parotid gland.
Both benign and malignant tumors can cause enlargement of the parotid gland. This may be due to inflammation, blockage of the salivary duct or as a space-occupying lesion it can increase the size of the parotid gland itself. A pleomorphic adenima is a benign tumor the parotid gland. Sometimes there may be hypertrophic lesions which are also benign.
There are several malignant (cancerous) tumors of the parotid gland including mucoepidermoid carcinoma (the most common parotid gland cancer), adenocarcinoma, adenoid cystic carcinoma, malignant mixed tumors, acinic cell carcinoma, primary squamous cell carcinoma, sebaceous carcinoma and salivary duct carcinoma. Some of these cancers are rare.
Autoimmune diseases can affect the parotid gland leading to inflammation and disturbing its function. This is seen in a condition known as Sjogren’s syndrome, which also affects the tear ducts. In this condition the immune system targets the gland tissue thereby causing inflammation and swelling usually arises. Sarcoidosis is a less common condition affectig the parotid where hard tissue known as granulomas arise in the affected organ.
- Alcohol abuse
- HIV and AIDS
- Kidney disease
- Liver disease
Treatment of Swollen Parotid Gland
There is no single treatment for all causes of parotid gland swelling. Treatment is dependnt on the underlying cause and may vary greatly. For example, antibiotics may be used for bacterial infections while corticosteroids and immune-modulating agents may be prescribed for autoimmune conditions. Surgery may also be necessary, especially where stones or tumors have to be removed.