The specific symptoms of damage to either the parotid gland or its duct would depend on the nature of the damage, as well as the location of the damage. In the broadest terms, the parotid gland may be affected by viral infection (usually mumps), bacterial infection (usually due to retrograde intrusion of oral bacteria into the duct), and more rarely (at least in the U. S), fungal or mycobacterial infection. The parotid gland also may be affected by inflammatory disease, such as sarcoidosis or Sjögren's syndrome, benign or malignant neoplastic disease, or physical trauma. The parotid gland can also be affected by the formation of stones, or "calculi", within the gland or any of the tributaries of its duct system.
Because of the wide variety of issues which may befall the parotid gland, the symptoms may vary accordingly. For example, tumors of the glands usually cause no symptoms until conspicuous swelling calls attention to their presence. In the case of parotid malignancy, these tumors have a predilection for affecting neighboring nerves, and may cause motor or sensory neuropathies, leading to either pain, numbness, or facial muscle weakness.
Perhaps one of the more conspicuous symptoms is pain or swelling. In the case of a stone causing parotid duct obstruction, patients often experience cyclical swelling and pain and then resolution before and after mealtime, when salivary secretion is stimulated. Depending on the degree of obstruction, dryness of the mouth may be noticed.
Diagnosis of parotid disease may entail a combination of imaging techniques, physical examination, immunologic tests, and sometimes biopsy, depending on the diagnosticians suspicions.
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