What is Deep Neck Infections?
Deep neck infections are a serious, but manageable group of infections that affect the deep tissues in the neck. They can quickly become very severe and lead to life-threatening issues. Despite being quite treatable, these infections are a considerable health concern because they can cause serious illness or even be fatal. These infections typically start because of other infections that spread from areas like the tonsils, saliva glands, neck lymph nodes, or tooth-associated structures.
These infections usually cause symptoms based on how they press on the throat, nerves, or digestive system. Common symptoms might include swelling or hardening in the neck, difficulty swallowing, changes in voice, and difficulty opening the mouth. The specific symptoms a person experiences can vary based on the exact location of the infection in the neck (like around the throat, behind the throat, in front of the spine, under the chin, or near the jaw muscles).
What Causes Deep Neck Infections?
Deep neck space infections, which are infections that occur deeper inside the neck, often involve different types of bacteria. These infections typically come from the normal bacteria found in our mouths and upper breathing passages. In adults, these infections often originate from dental and gum issues, while in children, they commonly come from tonsil and throat problems.
Many different types of bacteria can cause these infections, including Streptococcus viridans, Staphylococcus aureus, Klebsiella, and Fusobacterium species. These bacteria are usually part of the normal bacterial community in our mouths and throats, but problems can occur when they grow too much.
Less commonly, other types of bacteria and fungi can also lead to deep neck space infections. As with most infections, certain factors can make someone more likely to get sick. These include having a weaker immune system, diabetes, using intravenous drugs, and where the infection first started.
Risk Factors and Frequency for Deep Neck Infections
Deep neck infections are a serious health concern, leading to around 3,400 hospital stays each year in the United States. One study discovered a significant rise in the incidence of retropharyngeal abscesses, a type of deep neck infection, from 0.1 cases per 10,000 people in 2000 to 0.22 cases per 10,000 people in 2009. Furthermore, there were 0.94 cases of peritonsillar abscesses per 10,000 people and 0.14 cases of parapharyngeal abscesses per 10,000 people in 2009.
- Deep neck infections lead to approximately 3,400 hospitalizations each year in the US.
- The rate of retropharyngeal abscesses more than doubled from 0.1 cases per 10,000 people in 2000 to 0.22 cases per 10,000 people in 2009.
- In 2009, there were 0.94 peritonsillar abscess cases and 0.14 parapharyngeal abscess cases for every 10,000 individuals.
Signs and Symptoms of Deep Neck Infections
Various infections can present differently depending on several factors, such as where the infection is located, how extensive it is, and if there are other health problems present. Symptoms often include fever and neck pain. Other associated signs like tooth pain, difficulty swallowing, voice changes, jaw stiffness, pain during neck movements, and breathing difficulties may help to pinpoint the exact location of the infection. Doctors also look for potential risk factors such as a weakened immune system, recent dental procedures or neck trauma, recent neck surgery or radiation, IV drug use, or diabetes.
Patients might have a fever and look unwell. The neck might look uneven, red, swollen, or hardened, and there may be swelling in the regional lymph nodes. Neck stiffness could also occur. Abscesses, which are pockets of infection, can be difficult to spot in this area because they might be located deep beneath the skin and muscles. Computed tomography, commonly known as a CT scan, can identify these abscesses quite easily, so doctors may order this type of imaging for patients who can lie flat and have no difficulty protecting their airway.
- Fever and neck pain
- Tooth pain
- Difficulty swallowing
- Voice changes
- Jaw stiffness
- Pain during neck movements
- Breathing difficulties
- Risk factors like weakened immune system or diabetes
- Uneven, red, or swollen neck
- Swelling in the regional lymph nodes
- Neck stiffness
Upper deep neck infections that are near the tonsils, pharynx, parotid gland, and submandibular region typically trigger a sore throat and sometimes trismus, which is stiffness of the jaw. Local signs such as swelling on the neck or lower face, redness, tenderness, and swollen regional lymph nodes can be observed. If the uvula (the small, teardrop-shaped piece of soft tissue hanging down in the back of the mouth) shifts towards one side or if the wall of the pharynx moves inward, it can indicate a specific type of infection. These types of pressure could cause pain or difficulty swallowing, and may also result in inflammation in the joints located in the larynx. If the infection affects the vagus nerve, voice changes and hoarseness – known as ‘hot potato’ voice – can occur.
Problems such as infections in the submandibular space can occur after an infection spreads from a dental abscess, salivary glands, or oral injuries. If this kind of infection originates from the molar at the very back of the mouth, it could lead to Ludwig’s angina – a condition that can obstruct the airway if untreated. This condition is characterized by drooling, inability to swallow, jaw stiffness, and a hardened and raised floor of the mouth.
Infections at the back of the throat (parapharyngeal and retropharyngeal space) occur more often in children and are typically preceded by a respiratory infection. Symptoms may include difficulty swallowing, drooling, and abnormal breathing sounds, which can compromise the airway or even spread to the chest, leading to a condition called mediastinitis. The ‘danger space’, which is an area located between the back of the throat and the front of the prevertebral space, is highly susceptible to infection due to its loose tissue structure. This allows for rapid spreading of the infection to surrounding regions, causing severe complications such as mediastinitis, empyema (pus in the chest cavity), and sepsis (a severe and systemic response to infection).
Testing for Deep Neck Infections
If a doctor suspects that a patient has an infection, they will usually order a complete blood count (CBC) test. This test often shows an increase of white blood cells, indicating the body’s response to the infection. Additionally, the chemistry of a patient’s blood might show signs of dehydration if the patient hasn’t been drinking enough fluids due to pain. If the infection has spread to the bloodstream, which is known as being septic, the doctor may also take a blood culture. Any discharge from the infected area should also be cultured for a more accurate diagnosis.
X-rays of the neck can be used to check for infections, especially in children. These x-rays can hint at a behind-the-throat infection if the area between the spine and windpipe is larger than usual. The presence of any foreign object or air under the skin can also be checked using X-rays. In cases where there is a suspected lung area infection or a fluid-filled sac, a chest x-ray might be needed.
Ultrasound may be useful for infections close to the skin surface as it can help distinguish between inflammation tissue and abscesses. However, it may not work as well for deeper infections. If the ultrasound results are not clear, a CT scan can provide a more detailed image, as long as it’s safe for the patient.
The best imaging technique to diagnose a deep neck infection and understand its severity is the CT scan with contrast. This method gives very detailed images. An MRI might also be used, though this method can be harder to organize. A CT scan without contrast isn’t as helpful because it doesn’t clearly show the differences between tissue inflammation and abscesses.
Treatment Options for Deep Neck Infections
The main treatments for deep neck infections involve using targeted antibiotics, draining pus-filled pockets (abscesses), and providing strong supportive care. Doctors usually start with a particular set of antibiotics based on what bacteria they think is causing the infection and how resistant that bacteria might be to medicine in their area. They then adjust the treatment as needed, once they know what the specific bacteria is and how it responds to different drugs. However, what exact antibiotics to use hasn’t been rigorously studied in trials. That said, combinations of nafcillin or vancomycin with gentamycin or tobramycin, or ampicillin/sulbactam, or clindamycin, are usually the first options. In cases where the infection might be caused by methicillin-resistant Staphylococcus aureus (MRSA), a type of bacteria resistant to many antibiotics, a combination of vancomycin or linezolid with cefepime is typically used.
For patients who are at higher risk for MRSA infection, for example, those with diabetes, a history of injecting drugs, or living in an area or hospital where MRSA is common, including MRSA coverage in the initial treatment is important. Usually, antibiotics are administered for 2 to 3 weeks for most deep neck infections. In some cases, particularly when there are complications, longer periods may be needed. Once the patient begins to improve significantly and can comfortably eat, the antibiotics can be given orally instead of intravenously. It’s important to consult with a surgeon specializing in head and neck surgeries, as operation may be necessary if antibiotics don’t show improvement after 48 hours. Most deep neck abscesses, except for the very small ones, need to be surgically drained, whereas small or uncertain abscesses often respond well to aggressive medical treatment.
In acute situations, ensuring the patient’s airway is secure is always the top priority. Patients with deep neck infections, especially those with infections in the area under the jaw or those originating from a dental source, must have their airways protected. This usually involves inserting a tube into the trachea (windpipe) to aid breathing, often performed while the patient is awake, using a lighted fiberoptic instrument. The use of steroids to relieve symptoms in individuals with acute airway obstruction from neck infection is often debated and not backed by solid evidence. Therefore, any patient with a deep neck abscess, who also shows even mild airway symptoms, should have their airway secured first before draining the abscess.
What else can Deep Neck Infections be?
The possible causes of deep neck infections can vary, depending on the symptoms that a person is experiencing. If someone has a sore throat with fever, possible causes could be:
- Meningitis (an infection of the protective membranes covering the brain and spinal cord)
- Apical pneumonia (a type of pneumonia that affects the top of the lungs)
- Subarachnoid hemorrhage (a severe type of stroke caused by bleeding in the brain)
For acute (sudden) neck pain, especially if one side hurts more than the other, it could be due to:
- Trauma leading to neck fractures or dislocations
- Neck muscle hematomas (a collection of blood outside of a blood vessel)
- Strains in the neck muscles.
If a person comes in with a high-pitched wheezing sound when breathing (stridor), it might be because of:
- Acute epiglottitis (swelling of the flap at the base of the tongue)
- Bacterial tracheitis (a bacterial infection of the windpipe)
- Croup (a viral infection of the voice box)
For those who have significant pain or difficulty while swallowing, the doctors would consider checking for:
- Foreign body ingestion
- Acute esophagitis (inflammation of the esophagus).
If a person has a neck swelling and/or lump, then it’s always crucial for the healthcare professional to rule out the possibility of cancer.
What to expect with Deep Neck Infections
The outlook can vary greatly based on the individual’s immune system health and the severity and location of the infection. Death rates can range from 1% to 25%.
Possible Complications When Diagnosed with Deep Neck Infections
Infections in the side of the throat (known as lateral pharyngeal space infections) may spread to the sheath around the carotid artery in the neck and lead to a severe infection of the vein (septic thrombophlebitis), similar to Lemierre syndrome, and cause decay. Infections in the area behind the throat or the so-called danger space can move downwards to the area between the lungs (mediastinum), leading to acute mediastinitis. If this infection spreads further, it can cause pus-filled inflammation in different parts of the body, known as empyema, and inflammation of the sac which envelopes the heart (pericarditis). Other risks include breathing issues due to blocked airways and systemic infection that can lead to widespread inflammation throughout the body (sepsis) and infections in the brain.
Potential Complications:
- Severe infection of the veins (Septic thrombophlebitis)
- Decay
- Acute inflammation between the lungs (Acute mediastinitis)
- Pus-filled inflammation in different parts of the body (Empyema)
- Inflammation of the sac enveloping the heart (Pericarditis)
- Blocked airway leading to breathing issues
- Systemic infection leading to widespread inflammation (Sepsis)
- Infections in the brain
Preventing Deep Neck Infections
Maintaining good oral hygiene and getting early treatment for tooth decay and mouth infections can assist in preventing serious infections in the neck.
