Differential Diagnosis
- Single most likely diagnosis
- Acute bacterial sialadenitis: This is the most likely diagnosis given the patient's symptoms of swelling, pain, and tenderness in the left submandibular gland, along with the expression of pus from the Wharton duct. Sjögren's syndrome increases the risk of sialadenitis due to decreased saliva production, which can lead to bacterial overgrowth and infection.
- Other Likely diagnoses
- Sialolithiasis: The patient's symptoms could also be consistent with a salivary stone (sialolith) obstructing the Wharton duct, leading to inflammation and infection of the submandibular gland. The presence of Sjögren's syndrome may increase the risk of stone formation.
- Chronic sialadenitis: Given the patient's history of Sjögren's syndrome, chronic inflammation of the salivary gland is possible, and the current symptoms could represent an exacerbation of this condition.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Necrotizing sialometaplasia: Although rare, this condition can mimic an infection and is characterized by necrosis of the salivary gland tissue. It requires prompt diagnosis and treatment to prevent further tissue damage.
- Malignancy (e.g., adenocarcinoma or lymphoma): Although less likely, it is crucial to consider the possibility of a malignant process, especially in a patient with a history of Sjögren's syndrome, which has an increased risk of lymphoma.
- Rare diagnoses
- Sjögren's syndrome-associated lymphoepithelial lesions: These are rare lesions that can occur in patients with Sjögren's syndrome and may present with swelling and pain in the salivary glands.
- Granulomatous sialadenitis (e.g., due to sarcoidosis or tuberculosis): These conditions are rare but can cause inflammation and enlargement of the salivary glands, and should be considered in the differential diagnosis, especially if the patient has a history of exposure to tuberculosis or has systemic symptoms suggestive of sarcoidosis.