Peritonsillar abscess and tonsillitis are related to throat conditions that, while sharing some symptoms, are distinct and require their own understanding and management. Tonsillitis, characterized by inflammation of the tonsils due to an infection, often precedes or accompanies the development of a peritonsillar abscess (PTA), a collection of pus in the throat near the tonsils which demands immediate and specialized medical attention.

What is tonsillitis?

Tonsillitis, known medically as tonsillopharyngitis, is a common condition in which the tonsils become infected. Tonsils are the lumps of soft tissue at the back of the throat, one on each side, and during tonsillitis they can become swollen and sore, which makes it difficult to eat and swallow. 

 Tonsillitis can be caused by many types of bacteria or viruses, such as those that cause the common cold or flu. However, not all infections with these microbes lead to tonsillitis. Viral infections make up 70% of tonsillitis cases, which tend to have milder symptoms than bacterial infections. Bacterial tonsillitis, also sometimes called strep throat, due to a type of bacteria known as group A streptococcus being the main causative agent, is rarer and can cause severe infection.¹

How does tonsillitis spread?

Tonsillitis is spread by the transfer of infectious microbes from one person to another. In itself, tonsillitis is not infectious, just the microbes that cause it, so it is possible to get tonsillitis from someone who does not have it. That asymptomatic individual may be carrying the virus or bacteria in their nose, mouth, or throat. The most common ways that these viruses or bacteria are spread include: 

• Sharing of utensils, food, or drinks
• Coming into close contact with someone who is ill, particularly by inhaling infectious droplets spread through coughing or sneezing 
• Kissing someone with an infection
• Touching a surface containing the microbe and then touching your face which allows the infection into your body through the nose or mouth

Symptoms of tonsillitis 

The main symptoms of tonsillitis include:

• Sore throat 
• Fever
• Nausea 
•  Trouble swallowing
• Headache/earache 
• Tiredness 

If the infection is more severe, symptoms can include:

• Swollen lymph nodes (glands in the side of the neck causing the neck to look puffy) 
• White spots on the tonsils 
• Bad breath
• Snoring due to swollen glands blocking the airways 
• Sleep apnoea 

Treatment 

Usually, tonsillitis will get better on its own after a few days. During this time, it is important to get plenty of rest to allow the body to recover from the infection. Symptoms of mild tonsillitis can be managed by:

• Drinking cool drinks or eating ice lollies to soothe the pain
• Taking painkillers 
• Gargling with salt water to keep the area clean (though this is not advised for children) 

If the swelling becomes too severe to eat and sleep normally, you should seek medical help immediately. Antibiotics may be needed if there is a severe bacterial infection.¹ 

In the case of severe, chronic, recurring tonsillitis, medical providers will often advise a tonsillectomy, which is a surgery to remove the tonsils to prevent a recurrence of this infection.¹ This significantly reduces the risk of contracting throat infections in the future but comes with its own list of complications and side effects, so is not used as a routine treatment for tonsillitis. 

Complications 

In rare cases, serious complications can arise as a result of infectious tonsillitis, such as:

• Obstructive sleep apnoea, causes narrowing of the airways at night and issues with getting enough oxygen. This affects the quality of life due to a lack of sleep²
• Tonsil stones, or tonsilloliths, which are small buildups of debris in the tonsils 
• Tonsillar cellulitis, an infection of the tissues surrounding the tonsils, is often thought to be a transition phase between tonsillitis and a peritonsillar abscess³ 
• Peritonsillar abscess is the formation of an abscess in the throat secondary to a tonsillitis infection. This is very serious and requires medical intervention³

Peritonsillar abscess

Peritonsillar abscess (or PTA) is the most common infection of the head and neck,⁴ and occurs when microbes (usually bacteria) become trapped in the soft tissues of the throat and cause a buildup of pus.⁴ This leads to a large lump in the back of the throat. This is a severe complication of tonsillitis which requires medical treatment to be resolved. This condition is often referred to as “quinsy”.³

Symptoms ⁴ 

• Sore throat, particularly on one side, often accompanied by ear pain 
• Difficulty swallowing and opening the mouth
• Muffled voice, as if there is something stuck in the throat– in severe cases, the voice can be lost altogether
• Fever 
• General illness 
• Tiredness 
• Drooling from pooled saliva in the mouth because of difficulty swallowing
• Neck swelling, pain, and tenderness over affected lymph nodes
• Foul-smelling breath

These symptoms are progressive and will continue to worsen until treatment is obtained. Doctors are usually able to diagnose peritonsillar abscesses based on clinical presentation and examination of the abscess but may retrieve a sample of the pus to test for specific bacteria. This knowledge can help physicians prescribe the ideal treatment. 

Risk factors 

While PTA is not necessarily dependent on having an infection in the throat, there are some factors which make an individual more likely to develop the condition from simple bacterial or viral infections. ⁵ These include:

• Age - people from their mid-teens up to 40 years of age are most likely to develop PTA
• Gender - males are more likely to suffer from this condition 
• History of periodontal disease- an infection of the gum which causes damage to the area around the teeth
• Smoking
• Immunosuppression (a decreased ability by the body to recognize and attack foreign microbes) - including any health conditions or medications which may weaken the immune system, as this makes it harder for the body to clear the infection before it has the opportunity to develop into PTA
• Previous use of antibiotics

Treatment options⁴

Depending on the severity of the infection, patients can either be treated in an outpatient setting or require admission to the hospital. The most common reasons for hospitalization are dehydration caused by difficulty swallowing, airway obstruction due to swelling, and failure of outpatient management to treat the PTA. Treatment options include: 

• Antibiotics are used to clear bacterial infections
• Steroids may often be used to help speed up the rate of recovery and reduce hospital stays because of their ability to reduce swelling and inflammation
• Drainage – this is used for patients with abscesses larger than 1 cm and involves manually draining the pus from the throat. This is usually done as a needle aspiration in which a needle is used to draw out the pus; however, an incision may be made with a scalpel if the needle aspiration is unsuccessful
• Tonsillectomy – this is not common anymore but if a patient has recurrent tonsillitis and associated PTA it is recommended that the tonsils be surgically removed

If treatment is done in an outpatient setting, the patient should be observed for a few hours after treatment to make sure they are able to drink fluids and tolerate the medications given. Another important item to have available, since these procedures are occurring in the throat, is respiratory support in case the patient begins to show signs of respiratory distress such as difficulty breathing.

Complications⁴ 

Complications of PTA can be serious and life-threatening. It is important to get treatment for the condition before it becomes severe. Some of these complications include: 

• Airway obstruction which causes difficulty breathing
• Pneumonia is caused by the abscess bursting and infecting the lung. This can also cause a secondary abscess in the lung
• Spread of infection into the deep tissues of the neck
• Possibly fatal bleeding (haemorrhage) caused by the surrounding tissue (mainly the carotid artery) being worn away or damaged beyond repair

Summary 

• Tonsillitis is a common infection of the tonsils caused by either a viral or bacterial infection
• Peritonsillar abscesses can occur as a complication of tonsillitis. In this case, pus builds up in the back of the throat which causes issues with eating, drinking, and in severe cases, breathing
• PTA has severe complications such as pneumonia and airway blockage. Early medical intervention is vital
• Patients can be treated in an outpatient setting or may be admitted to the hospital for a few days depending on the severity of the infection
• The abscess can be treated with steroids and antibiotics as well as manual drainage of the pus. 
• Tonsillectomy may be required to prevent recurring infections