Sialadenitis is inflammation of the salivary glands, most commonly involving the parotid, submandibular, or sublingual glands. It may present as an acute or chronic condition and arises from a range of infectious, obstructive, and autoimmune causes that disrupt normal salivary flow.

Common Causes

Understanding the etiology of sialadenitis is essential for selecting the correct treatment. The condition falls into several distinct but overlapping categories:

• Bacterial infection: The most frequent cause of acute sialadenitis, typically involving Staphylococcus aureus or oral streptococci, and often precipitated by dehydration or reduced salivary flow in debilitated patients.
• Viral infection: Mumps (paramyxovirus) is the classic viral culprit, producing bilateral parotid swelling; other viruses including HIV can also affect glandular tissue.
• Obstructive sialadenitis: Ductal blockage caused by sialolithiasis (salivary stones) impedes secretion, creating conditions favorable to bacterial overgrowth and subsequent inflammation.
• Autoimmune disease: Conditions such as Sjögren’s syndrome drive chronic lymphocytic infiltration of glandular tissue, resulting in recurrent episodes of sialadenitis and significant xerostomia (dry mouth).
• Granulomatous sialadenitis: Sarcoidosis and tuberculosis can infiltrate the glands, producing a slow, non-infectious inflammatory response.

Clinical Presentation

Acute bacterial sialadenitis typically presents with rapid-onset unilateral pain, firm swelling over the affected gland, erythema of the overlying skin, and systemic signs such as fever and malaise. Gentle bimanual palpation of the gland may express purulent saliva from the duct orifice — a hallmark clinical finding. Chronic and autoimmune-related forms tend to progress more insidiously, with episodic swelling and gradual loss of glandular function over time.

Diagnosis and Management

Diagnosis begins with a thorough clinical examination, often supported by ultrasound or CT imaging to detect ductal obstruction, abscess formation, or gland enlargement. When sialolithiasis is identified as the obstructing factor, stone removal is a prerequisite for full resolution of the inflammation. Laboratory workup may include a complete blood count, culture of expressed secretions, and autoimmune serologies such as anti-SSA/SSB antibodies when Sjögren’s syndrome is suspected.

Treatment is cause-directed: bacterial sialadenitis typically responds to antibiotic therapy, aggressive hydration, sialagogues, gland massage, and warm compresses; viral forms are managed supportively; autoimmune-driven disease requires systemic therapy aimed at the underlying condition. Prompt recognition and management of sialadenitis is critical to preventing progression to abscess formation, chronic gland fibrosis, or permanent loss of salivary function — all of which carry meaningful consequences for oral health and overall quality of life.