Retropharyngeal Abscess

What a retropharyngeal abscess is

Behind the throat lies a narrow space, the retropharyngeal space, between the throat lining and the muscles covering the spine. In young children, it contains small lymph nodes that drain the nose, sinuses, adenoids and middle ear. When these nodes become infected after a cold or ear infection, they can swell and turn into a pocket of pus.

These lymph nodes shrink after about age 5, which is why the condition is much rarer in older children and adults.

The space runs down from the base of the skull into the chest. That is what makes the infection dangerous: pus can spread downward into the area around the heart and lungs (the mediastinum).

Causes

In children

• upper respiratory infections and colds
• sore throat, tonsillitis or pharyngitis
• middle ear and sinus infections
• injury from falling with a pencil, stick or toy in the mouth

In adults

• injuries to the back of the throat from fish or chicken bones
• medical procedures such as intubation, endoscopy or dental work
• spread of a dental or tonsil infection
• weakened immunity from diabetes, HIV, cancer treatment or steroids

The bacteria usually involved are group A Streptococcus, Staphylococcus aureus (including MRSA) and anaerobic bacteria that live in the mouth. Often several are present together.

Symptoms

Symptoms usually develop over a few days, often just as a cold seems to be ending:

• fever
• sore throat and painful swallowing
• refusing to eat or drink
• drooling
• neck stiffness or reluctance to move the neck, especially to tilt the head back, which can be mistaken for meningitis
• a tilted head (torticollis)
• swollen neck glands
• a muffled voice
• noisy breathing or stridor when the airway is narrowed
• irritability in young children

How it differs from similar conditions

Diagnosis

Doctors look in the throat (carefully, since examination can upset a child with a threatened airway), check the neck and assess breathing. Tests include:

• CT scan of the neck with contrast: the main test. It shows whether there is a drainable abscess or only swollen, inflamed tissue (phlegmon), and whether it has spread.
• Lateral neck X-ray: may show widening of the soft tissue in front of the spine, but it is less accurate.
• Blood tests: white blood cell count, inflammatory markers and blood cultures.

If the airway is at risk, securing breathing comes before any scan.

Treatment

Treatment takes place in the hospital.

• Airway protection: the most important step. Children with breathing difficulty are managed in the operating room or ICU, sometimes with a breathing tube.
• IV antibiotics: broad-spectrum antibiotics that cover strep, staph and anaerobic bacteria, for example ampicillin-sulbactam or clindamycin, with vancomycin added if MRSA is a concern. Many small abscesses and areas of phlegmon heal with antibiotics alone.
• Surgical drainage: an ear, nose and throat surgeon drains larger abscesses, those causing airway problems, or those that do not improve within 24 to 48 hours of antibiotics. Drainage is usually done through the mouth under general anesthesia. Some cases need an approach through the neck.
• Fluids and pain relief: IV fluids until the person can swallow, and acetaminophen (paracetamol) or ibuprofen at the label dose. Never give aspirin to children or teenagers.

After improvement, antibiotics are switched to tablets or liquid to finish a course, usually totaling about 2 weeks.

Complications

Without prompt treatment, a retropharyngeal abscess can cause:

• airway obstruction
• rupture of the abscess, with pus inhaled into the lungs (aspiration pneumonia)
• mediastinitis, a life-threatening infection in the chest
• blood clots in the jugular vein (Lemierre syndrome)
• erosion into the carotid artery
• spinal infection or abscess
• sepsis

Outlook and prevention

With early diagnosis and treatment, most children and adults recover fully within a week or two. Recurrence is uncommon. There is no specific prevention, but prompt treatment of bacterial throat and ear infections, keeping sharp objects out of children's mouths while they run, and care when eating fish reduce the risk.

Frequently asked questions

What are the symptoms of a retropharyngeal abscess?

Common symptoms are fever, sore throat, painful swallowing, drooling, refusing food and drink, a stiff neck that the person will not tilt back, swollen neck glands and a muffled voice. Noisy breathing or difficulty breathing means the airway is narrowing and needs emergency care.

Why are retropharyngeal abscesses more common in children?

Young children have lymph nodes in the retropharyngeal space that drain the nose, throat and ears. After a cold or ear infection, these nodes can become infected and form an abscess. The nodes shrink by about age 5, so the condition becomes much rarer in older children and adults.

Is a retropharyngeal abscess an emergency?

Yes. It can swell enough to block the airway or spread into the chest, causing life-threatening infection. Anyone with fever, sore throat and a stiff neck, drooling, or noisy breathing should be seen in an emergency department straight away.

How is a retropharyngeal abscess treated?

It is treated in hospital with IV antibiotics that cover the usual bacteria. Larger abscesses, or ones affecting breathing or not improving within 1 to 2 days, are drained surgically, usually through the mouth. Most people finish a total of about 2 weeks of antibiotics.

Can adults get a retropharyngeal abscess?

Yes, though it is less common. In adults it usually follows an injury to the back of the throat, such as from a fish bone, a medical procedure or a dental infection, or occurs in people with diabetes or weakened immunity. Symptoms and treatment are similar to those in children.