Preauricular lymph nodes: What to know

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.

The human body contains about 600 small glands called lymph nodes that play an essential role in the function of the immune system.

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.

Learn more about the anatomy of the lymphatic system and how it works in the body in this article.

Most healthy lymph nodes are so small that a person is unable to feel them.

Sometimes, a lymph node or multiple lymph nodes may swell as they work hard to remove harmful substances from the lymph fluid. The swelling usually signals a problem somewhere in the body.

Doctors use the term localized lymphadenopathy to refer to swelling in a single lymph node or a small cluster of lymph nodes, such as the PLNs.

Localized lymphadenopathy happens when there is a problem in nearby tissues. The issue may be:

• an infection
• injuries
• cancer

Generalized lymphadenopathy is swelling in multiple lymph nodes throughout the body. Certain infections, diseases, and medications can cause this type of swelling.

The following are potential causes of swelling in the PLNs:

Salivary gland infections

The parotid glands are a type of large salivary gland, and they sit over the upper jaw, one in front of each ear. Infections of the parotid glands can cause swelling of the PLNs.

Other possible symptoms of a salivary gland infection include:

• dry mouth
• an abnormal or foul taste
• swelling in front of the ears, below the jaw, or on the floor of the mouth
• a squeezing pain in the mouth or face, especially when eating
• difficulty opening the mouth
• redness on the side of the face or upper neck
• a fever

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

• poor oral hygiene
• blockages with salivary duct stones
• dehydration
• chronic illness
• smoking

Learn more about the causes, types, and symptoms of salivary gland infections here.

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:

• a swollen ear canal
• redness of the outer ear
• a blockage in the ear
• muffled hearing or hearing loss
• itching inside the ear
• discharge from the ear
• pain inside the ear, especially when touching the earlobe
• pain that radiates from the ear to the head, neck, or side of the face
• swelling of the lymph nodes in the neck

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

Learn all about how to treat and prevent swimmer’s ear in this article.

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 is usually the result of a viral or bacterial infection of the eye. Other causes include allergies and irritants.

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

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

• pink or redness in the whites of the eyes
• swelling of the conjunctiva or eyelid
• itching, burning, or irritation
• watery discharge from the eye
• an urge to rub the eye
• crusting of the eyelids or eyelashes, especially upon waking

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

Learn more about a variety of home remedies for conjunctivitis in this article.

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.

People with POS may also experience redness, tenderness, or inflammation of the eye, as well as fever and other signs of illness.

The most common cause of POS is cat scratch disease, 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:

• tularemia, or deer fly fever
• sporotrichosis
• tuberculosis
• coccidioidomycosis
• syphilis

Learn more about the signs and symptoms of cat scratch disease here.

Dental problems

Some dental problems can also cause the PLNs to swell. Dysodontiasis is a medical term that describes the painful, difficult, or delayed eruption of the teeth.

This dental problem may occur in children when their adult teeth are coming in or affect adults when they get their wisdom teeth.

In some cases, a fluid filled sac called a dentigerous cyst might develop between the jawbone and a partially erupted tooth.

Without treatment, the cyst may become infected, and 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

Lymphoma

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 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 following areas:

• neck
• armpit
• groin
• abdomen

Other symptoms include:

• loss of appetite
• unexplained weight loss
• pain in the abdomen
• indigestion and bloating
• nausea and vomiting
• abnormal pressure in the affected area
• congestion in the face, neck, and upper chest
• constant coughing
• flu-like body aches
• bone pain
• a recurrent or persistent fever
• night sweats
• itching
• fatigue

Learn more about the symptoms of lymphoma and its risk factors in this article.

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 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.

Lymphoma

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.

The PLNs are part of the body’s lymphatic system, which 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.