Parapharyngeal Abscess

Where the parapharyngeal space is

The parapharyngeal space is a funnel-shaped area on each side of the throat, running from the base of the skull down toward the hyoid bone in the upper neck. It contains fat, lymph nodes, nerves, the internal jugular vein and the carotid artery. It connects with other deep neck spaces, including the space behind the throat (retropharyngeal) and the space under the jaw, which is why infection can spread quickly.

Causes

• tonsillitis or a peritonsillar abscess that spreads outward
• dental infections, especially of the lower molars and wisdom teeth (tooth abscess)
• salivary gland infections (parotitis)
• infected lymph nodes in the neck
• recent throat, dental or neck procedures, or injury inside the mouth
• mastoiditis and infections of the upper airway

The usual germs are a mix of streptococci, staphylococci (including MRSA) and mouth anaerobic bacteria.

Risk factors

• diabetes
• weakened immune system
• poor dental health
• injection drug use in the neck

Symptoms

• fever and chills
• sore throat and painful swallowing
• swelling and tenderness on one side of the neck, below the angle of the jaw
• difficulty opening the mouth (trismus), caused by irritation of the jaw muscles
• neck pain and stiffness, especially turning the head
• a bulge in the side wall of the throat, pushing the tonsil toward the middle
• muffled ("hot potato") voice
• drooling
• in children: refusing to eat or drink, irritability, holding the neck still

Comparison with other deep neck infections

Diagnosis

• examination of the mouth, throat and neck, and of the airway
• CT scan of the neck with contrast: the key test to confirm an abscess, show its size and check for spread
• ultrasound in children or for superficial collections
• blood tests: white blood cell count, inflammatory markers and blood cultures
• culture of drained pus to guide antibiotics

Treatment

Airway first

Keeping the airway open is the top priority. Some people need monitoring in intensive care, and rarely a breathing tube or tracheostomy.

Antibiotics

IV antibiotics that cover streptococci, staphylococci and anaerobes are started immediately, then adjusted to culture results. Small abscesses, especially in children, sometimes resolve with antibiotics alone under close observation.

Drainage

Larger abscesses, those not improving within 24 to 48 hours, or those threatening the airway are drained:

• needle aspiration
• surgical drainage through the neck or the mouth, depending on location

Treating the source

Dental extraction or treatment, or later tonsillectomy, may be needed to prevent recurrence.

Complications

• airway obstruction
• mediastinitis: spread into the chest, a life-threatening complication
• Lemierre syndrome: a clot in the internal jugular vein with infected clots spreading to the lungs
• carotid artery erosion, causing major bleeding
• sepsis
• nerve damage

Outlook

With prompt CT diagnosis, antibiotics and drainage, most people recover fully. Delay in treatment increases the risk of serious complications. Good dental care and early treatment of throat infections reduce the risk.

Frequently asked questions

What are the symptoms of a parapharyngeal abscess?

Common symptoms are fever, sore throat, painful swallowing, swelling on one side of the neck below the jaw, difficulty opening the mouth, neck stiffness and a muffled voice. Trouble breathing or drooling is an emergency.

What causes a parapharyngeal abscess?

It usually develops when infection spreads from the tonsils, teeth, salivary glands or lymph nodes into the deep neck space beside the throat. Poor dental health, diabetes and weakened immunity increase the risk.

Is a parapharyngeal abscess dangerous?

Yes. Because it sits near the airway, major blood vessels and the chest, it can block breathing, spread to the chest, cause blood clots or erode an artery. It needs urgent hospital treatment.

How is a parapharyngeal abscess treated?

Treatment involves hospital admission, IV antibiotics, close airway monitoring, and drainage of the abscess with a needle or surgery when needed. The original source, such as an infected tooth or tonsils, is also treated.