The preauricular lymph nodes sit just in front of the ears. These tiny nodes play a vital role in protecting the body against infections and disease.

In this article, we provide information on the preauricular lymph nodes (PLNs) and other parts of the lymphatic system.

We also look at what conditions and health issues can cause the PLNs to swell.

illustration of head with lines pointing to different lymph nodesShare on Pinterest
Illustrated by Jason Hoffman

The human body contains about 800 small glands called lymph nodes. These play an essential role in the function of the immune system.

The PLNs are a group of lymph nodes that sit just in front of the ears. These lymph nodes filter lymph fluid as it arrives from the scalp, neck, and various parts of the face.

A network of vessels called the lymphatic system connects the lymph nodes.

Lymph vessels take excess fluid from the body’s tissues and direct it toward nearby lymph nodes. The lymph nodes contain immune cells that detect and destroy bacteria, viruses, and damaged cells in the fluid.

At the end of this filtering process, the lymph nodes release the clean fluid back into the blood.

Most healthy lymph nodes are so small that a person is unable to feel them. They typically are 1-2 centimeters (cm) in size.

Sometimes, a lymph node or multiple lymph nodes may swell as they work hard to remove harmful substances from the lymph fluid.

There are two types of swelling, which usually signal a problem somewhere in the body.

  • Localized lymphadenopathy refers to swelling in a single lymph node or a small cluster of lymph nodes, such as the PLNs. It happens when there’s a problem in nearby tissues, such as infection, inflammation, or cancer.
  • Generalized lymphadenopathy is swelling in multiple lymph nodes throughout the body caused by certain infections, diseases, and medications.

The following are potential causes of swelling in the PLNs.

Salivary gland infections

The parotid glands are a type of large salivary gland. They sit over the upper jaw, one in front of each ear.

Parotid gland infections may cause swelling of the PLNs.

Other possible symptoms of a salivary gland infection include:

Salivary gland infections are usually bacterial. Risk factors for these types of infection include:

Otitis externa

Otitis externa, or swimmer’s ear, is a condition that causes inflammation, irritation, or an infection of the ear canal. It can sometimes cause the lymph nodes around the ear to swell.

Other common symptoms include:

Otitis externa often occurs when water becomes trapped in the ear, leading to the growth of bacteria and fungi.

Viral conjunctivitis

Conjunctivitis, which people commonly call pinkeye, refers to inflammation or swelling of the conjunctiva within the eye. The conjunctiva is a thin membrane that covers the whites of the eyes.

Conjunctivitis may be caused by:

  • viral or bacterial infection of the eye
  • allergies
  • irritants

Viral conjunctivitis may cause the PLNs to swell and become tender.

Symptoms of viral conjunctivitis usually begin in one eye and spread to the other within a few days. These may include:

People with conjunctivitis may also experience symptoms of a cold, flu, or other respiratory infections.

Learn more about home remedies for conjunctivitis.

Parinaud oculoglandular syndrome

Parinaud oculoglandular syndrome (POS) is a type of conjunctivitis that usually affects one eye.

A person with POS may notice small tan nodules within the white of the eye and swelling of the nearby PLNs.

Other symptoms of POS may include:

  • redness, tenderness, or inflammation of the eye
  • fever
  • other signs of illness

The most common cause of POS is cat scratch fever, which can occur when a person receives a bite or scratch from a cat that exposes them to harmful bacteria.

Other causes of POS include:

Dental problems

Some dental problems can also cause the PLNs to swell.

For example, a fluid-filled sac called a dentigerous cyst might develop between the jawbone and a partially erupted tooth.

The cyst typically does not cause any symptoms. However, without treatment, the cyst may become infected. This infection can spread to the PLNs, causing them to swell.

Other symptoms of a dentigerous cyst include:

  • pain and swelling in and around the affected tooth
  • an accumulation of pus within the cyst
  • displacement of surrounding teeth


Most causes of swollen PLNs are due to viral or bacterial infections. However, in very rare cases, a painless swelling in any of the lymph nodes could be a sign of lymphoma.

Lymphoma is a cancer that originates in the cells of the lymphatic system. The most common types are Hodgkin lymphoma and non-Hodgkin lymphoma.

Lymphoma may occur in any lymph node, but it usually affects those in the neck, armpit, or groin.

People should see a doctor as soon as possible if they are experiencing any of the following symptoms:

  • nodes in the neck that cause difficulties breathing or swallowing
  • a fever over 104°F
  • a lymph node that gets much larger over 6 hours or less
  • redness of the skin covering the node

People should also speak to a doctor if they experience more than one swollen lymph node, or if a lymph node has any of the following characteristics:

  • measures at least 1 inch in diameter
  • feels tender to the touch
  • appears swollen without any obvious cause
  • lasts more than a month
  • limits the ability to move part of the body
  • comes with a fever lasting more than 3 days

The above symptoms may indicate a serious infection, which a doctor can help treat.

The type of treatment for a swollen PLN will depend on the underlying cause. In most cases, the lymph nodes return to their normal size with the right treatment.

Infectious causes

A doctor may prescribe antibiotics to treat bacterial infections. Resting, getting plenty of fluids, and taking over-the-counter (OTC) pain relievers can help a person recover from a viral infection.

Dental causes

For a dentigerous cyst, a doctor or dentist will usually refer the person to an oral surgeon.

The surgeon may drain the cyst or remove it entirely. They may also remove the unerupted tooth.


Treatment options for lymphoma will depend on the type and stage of the cancer. People should talk to their oncologist, a cancer specialist, for more information about their treatment plan.

What are the early warning signs of lymphoma?

A common sign of lymphoma is one or multiple swollen lymph nodes that are painless and do not go away. Other signs and symptoms include:

What causes posterior auricular lymph nodes to swell?

Posterior auricular lymph nodes may become swollen for a variety of reasons, such as:

  • salivary gland infections
  • ear infections
  • eye infections
  • dental problems
  • lymphoma

The PLNs are part of the body’s lymphatic system. This helps protect the body against infections and disease.

Many different conditions can cause swollen PLNs, but infections are the most common cause.

In most cases, the swollen node will return to its normal size once the underlying issue has resolved, often with treatment from a doctor.