Sialadenitis Guide: What to Know about Salivary Gland Infections

Medically Reviewed By Nicole Leigh Aaronson, MD, MBA, CPE, FACS, FAAP
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Sialadenitis is an infection of the salivary glands. It commonly occurs in older adults and people who are chronically ill. There are several causes, treatments, and ways to prevent sialadenitis. Sialadenitis is a salivary gland infection. It is sometimes caused by salivary gland stones or conditions that cause dry mouth.

This article explains what sialadenitis is and how you can prevent and treat this type of infection.

What is sialadenitis?

Person looking in the mirror as they brush their teeth
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Sialadenitis is a bacterial or viral infection of the salivary glands. It most commonly affects older adults and people who are chronically ill, have dry mouth, or are dehydrated.

There are many salivary glands. The major salivary glands come in pairs, one on each side of the face. The three major pairs of salivary glands are: 

  • Submandibular glands are located along the inner jawline. 
  • Parotid glands are found in front of the ear and jaw joint. 
  • Sublingual glands are found in the front of the jaw, under the tongue.

Sialadenitis is most common in the parotid glands. The most common bacteria that causes sialadenitis is Staphylococcus aureus.

The two types of sialadenitis are:

  • Chronic sialadenitis: This is characterized by recurrent or persistent infection of the salivary glands. It is usually caused by obstruction of the salivary glands and presents with swelling.
  • Acute sialadenitis: This is usually due to bacterial or viral infections and presents with a rapid onset of pain and swelling.

Sialadenitis of the submandibular gland accounts for 10% of all cases of sialadenitis and is less common than sialadenitis of the parotid glands. It is usually caused by multiple bacteria and affects older, dehydrated individuals.

What are the symptoms of sialadenitis?

The most common symptom of sialadenitis is swelling of the salivary glands. Other common symptoms include:

  • fever
  • chills
  • unilateral pain
  • redness on the overlying skin
  • drainage of pus from the infected gland

What causes sialadenitis?

The most common cause of sialadenitis is bacteria, usually Staphylococcus aureus. Viruses (such as mumps) and fungi can also cause sialadenitis. Infection usually happens when the mouth is dry. Dry mouth can be caused by:

  • a salivary stone blocking the gland
  • inadequate fluid consumption (being dehydrated)
  • illness
  • certain medications, such as diuretics
  • radiation therapy

Sjögren’s syndrome, an immune system disorder characterized by dry eyes and dry mouth, can also make sialadenitis more likely to occur.

What are the risk factors for sialadenitis?

Some people may be more at risk for developing sialadenitis. However, not all people with risk factors will go on to develop the condition. Some people commonly at risk include:

  • adults in their 50s or 60s
  • people with a chronic illness
  • people with Sjögren’s syndrome
  • young adults with anorexia

How do you prevent sialadenitis?

The best way to prevent sialadenitis is to stay hydrated and keep your mouth moist. Practicing good oral hygiene and visiting the dentist regularly can help ensure your mouth is healthy, and there are no signs of infection.

Contact your dentist if you experience mouth pain, especially when eating or drinking.

Sialadenitis is similar to and sometimes caused by salivary gland stones. Salivary gland stones are calcifications that obstruct the salivary glands.

Like sialadenitis, salivary gland stones are usually caused by dry mouth or certain medications that cause dry mouth.

The signs of salivary gland stones are similar to sialadenitis and include pain, swelling, tenderness of the salivary glands, and dry mouth.

Learn more details about salivary gland stones.

How do doctors diagnose sialadenitis?

Doctors diagnose sialadenitis by taking a detailed medical history, including any current medical conditions, prescription medications, over-the-counter (OTC) medications, or supplements you take.

Your doctor will look inside your mouth and examine your salivary glands, looking for signs of redness, swelling, or drainage.

A CT scan, ultrasound, or MRI can help confirm the presence of sialadenitis by providing an image of the inside of the mouth and neck.

If any drainage or pus comes from a salivary gland, your doctor can send a sample to a lab to be cultured. This will help identify the organism causing the infection, which helps decide the best course of treatment.

How do you treat sialadenitis?

Treatment for sialadenitis begins with a course of antibiotics, usually one that treats Staphylococcus aureus. These include dicloxacillin or clindamycin.

However, a different antibiotic will be used if the culture shows that a different organism is causing the infection. In cases where the individual has methicillin-resistant S. aureus (MRSA), Vancomycin can be used.

At-home remedies can also provide relief. These include:

  • drinking plenty of fluids to stay hydrated
  • using warm compresses to soothe painful areas
  • massaging the affected gland
  • sucking on hard candy, lemon, or ice cubes to trigger saliva flow (called sialagogues)
  • treat pain or swelling with acetaminophen (Tylenol) or ibuprofen(Advil, Motrin)

In some severe cases, surgical excision of the salivary gland may be necessary to drain an abscess after the infection is treated with antibiotics.

If salivary stones are present, a doctor may remove the stones by direct excision or by using a surgical procedure called a “sialoendoscopy.” If the infection persists, IV antibiotics and fluids may be necessary.

What are the potential complications of sialadenitis?

Some examples of complications that can occur from sialadenitis include:

  • Abscess formation. In some cases, the infection can spread outside the gland itself. In this case, surgical incision and drainage are usually required.
  • Dental decay. Reduced saliva production from sialadenitis decreases protection from acid erosion of the teeth. This makes dental decay more likely to occur.

Frequently asked questions

Here are some frequently asked questions people have about sialadenitis.

What is the difference between sialadenitis and parotitis?

Sialadenitis can affect any of the salivary glands. In contrast, parotitis affects only the parotid glands. Sialadenitis is usually caused by a bacterial organism, whereas mumps or bacteria are common causes of parotitis.

Can sialadenitis go away on its own?

Because sialadenitis is an infection, it is unlikely to go away without treatment. Treatment usually involves antibiotics if a bacterial organism causes the infection. Other treatments include home care, such as hydration, gentle massage, and warm compresses.

Does sialadenitis cause ear pain?

If sialadenitis affects the parotid glands, which are glands in front of the ear, it may cause some ear pain. Treating the infection in the early stages can help resolve ear pain.


Sialadenitis is an infection of the salivary glands. A bacterial or viral organism usually causes it. Sialadenitis can also be caused by dehydration or dry mouth and is more common in older adults or people who are chronically ill.

Diagnosis involves a physical exam of the salivary glands, imaging tests, and possibly a lab culture. Sialadenitis is most commonly treated with a combination of antibiotics and at-home care. In some severe cases, such as when an abscess has formed, surgical excision, drainage, stone removal, or gland removal may be necessary.

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Medical Reviewer: Nicole Leigh Aaronson, MD, MBA, CPE, FACS, FAAP
Last Review Date: 2022 Oct 28
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