Pharyngitis is inflammation of the mucous membranes that line the back of the throat, or pharynx. This inflammation can cause discomfort, dryness, and difficulty swallowing.

Pharyngitis is the medical term for a sore throat. Causes of pharyngitis include viral infections, such as common colds, and bacterial infections, such as group A Streptococcus.

Pharyngitis is a common condition and rarely a cause for concern. Viral pharyngitis often clears up on its own within a week or so. However, knowing the cause can help people narrow down their treatment options.

This article looks at the causes, transmission, and symptoms of pharyngitis. We also cover similar conditions, diagnosis, treatment, and prevention.

Share on Pinterest
Catherine McQueen/Getty Images

Viral infections are the most common cause of pharyngitis. Some common viruses that can cause pharyngitis include:

  • rhinovirus, coronavirus, or parainfluenza, which are causes of the common cold
  • adenovirus, which can cause conjunctivitis, also known as pink eye, and the common cold
  • influenza, or the flu
  • Epstein-Barr virus, which causes mononucleosis

Mononucleosis, or mono, is a contagious viral infection that causes a range of flu-like symptoms. The virus can spread through saliva, so a person can contract it by sharing utensils and cutlery, exposure to coughs and sneezes, or by kissing. Also known as the kissing disease, mononucleosis mostly affects teenagers and young adults, but also affects children.

While less common, bacterial infections can also cause pharyngitis. Group A Streptococcus bacteria is responsible for pharyngitis in children around 20–40 percent of the time. People commonly refer to pharyngitis caused by group A Streptococcus infection as strep throat.

Other bacterial infections that can cause pharyngitis include:

Factors that can increase a person’s risk of pharyngitis include:

  • having a history of allergies
  • having a history of frequent sinus infections
  • smoking or exposure to secondhand smoke

Both viral and bacterial forms of pharyngitis are contagious. The germs that cause pharyngitis tend to live in the nose and throat.

When a person with the condition coughs or sneezes, they release tiny droplets that contain the virus or bacteria into the air. A person can become infected by:

  • breathing these tiny droplets in
  • touching contaminated objects and then touching their face
  • consuming contaminated food and beverages

This is why it is essential for a person to wash their hands before handling food or touching their face.

People usually recover from viral infections, such as the common cold, within 7-10 days. However, due to the viral incubation period, people may be contagious before any symptoms appear.

According to the Centers for Disease Control and Prevention (CDC), a person can help prevent spreading strep throat to other people by staying home until they no longer have a fever and have been taking antibiotics for at least 24 hours.

The main symptom of pharyngitis is a sore, dry, or itchy throat. Additional symptoms may appear depending on the type of infection, such as cold or flu symptoms.

Symptoms of viral pharyngitis include:

  • a cough
  • a headache
  • runny nose
  • eye irritation
  • swollen tonsils
  • post nasal drip
  • swollen lymph nodes
  • fatigue

Pharyngitis associated with mononucleosis can have additional symptoms including:

  • abdominal pain, especially on the upper left side
  • overwhelming fatigue
  • poor appetite
  • swollen lymph nodes
  • rash

Symptoms of bacterial pharyngitis may include:

  • significant pain when swallowing
  • tender, swollen neck lymph nodes
  • visible white patches or pus on the back of the throat
  • tonsils that are swollen and red
  • a headache
  • abdominal pain
  • fatigue
  • nausea
  • vomiting
  • rash, which is known as scarlet fever or scarlatina

Inflammation of the throat is a common medical issue, and it can result from a variety of causes. Other possible causes can include:

Laryngitis

Laryngitis is a condition that causes inflammation in the larynx or voice box. The larynx sits in the front of the throat, above the windpipe, and it contains the vocal cords.

Inflammation of the vocal cords can cause hoarseness of the voice, and some people may even lose their voice temporarily.

People can get laryngitis from straining their vocal cords by yelling or overusing their voice.

Other causes of laryngitis include:

  • allergies
  • stomach acid from acid reflux
  • viral infections
  • bacterial infections

Tonsillitis

Tonsillitis is an inflammation of the tonsils. The tonsils are collections of tissue that sit on either side of the pharynx. Tonsillitis is the result of either a viral or bacterial infection. Bacterial tonsillitis can also result from infection with group A Streptococcus bacteria.

Tonsillitis is rarely serious and often clears up on its own or with a short course of oral antibiotics. However, a doctor may recommend surgical removal of a person’s tonsils if the condition is long-term or keeps recurring. Recurring tonsillitis may be defined as seven episodes in one year, five episodes in two years, or three episodes in three years. A child’s school absences may also be a factor in a medical professional’s decision to recommend removal.

If an abscess develops on the tonsils, it could require surgical drainage.

Symptoms of tonsillitis and pharyngitis are similar. Tonsillitis is effectively a subset of pharyngitis. Symptoms of both include:

  • a sore throat
  • red and swollen tonsils
  • white or yellow dots on the tonsils
  • difficulty swallowing
  • abdominal pain
  • a headache
  • stiffness of the neck

Throat ulcers

An ulcer is a pus-filled sore that can form on the throat, mouth, vocal cords, or food pipe. Causes of throat ulcers include:

  • viral or bacterial infections
  • damage to the tissue lining the throat
  • chemotherapy
  • stomach acid from vomiting or acid reflux

Symptoms of throat ulcers are similar to pharyngitis. They include:

  • difficulty or pain when swallowing
  • white patches in the throat
  • fever
  • chills
  • swollen lymph nodes
  • nausea

People with pharyngitis should contact their healthcare provider if they experience any of the following:

  • symptoms lasting more than 10 days
  • severe difficulty or pain when swallowing
  • difficulty breathing
  • rash
  • inability to drink
  • inability to swallow secretions
  • difficult opening mouth
  • voice changes

Sore throats can result from a variety of underlying medical conditions. While viral infections are the most common cause of pharyngitis, it is still important to correctly diagnose the cause in order to treat the condition successfully.

A doctor will usually begin diagnosing pharyngitis by performing a physical examination. They will review the person’s current symptoms and check their throat, ears, and nose for signs of infection.

When an individual has clear signs of a viral infection, the doctor will likely not perform further testing.

If the doctor suspects a bacterial infection, they may order a throat culture to confirm the diagnosis. This involves taking a swab of a person’s throat and sending it to a lab for analysis.

The appropriate treatment for pharyngitis varies depending on its underlying cause.

For bacterial infections, a doctor may prescribe a person a course of oral antibiotics, such as amoxicillin or penicillin. The antibiotics help reduce symptoms and prevent complications, such as rheumatic fever.

It is essential to complete the entire course of antibiotics to ensure the infection has cleared and to prevent reinfection.

Viral pharyngitis does not respond to antibiotics and will typically clear up on its own. However, over-the-counter medications, such as acetaminophen or ibuprofen, can help reduce pain and fever.

Home remedies that may help speed up recovery include:

  • getting plenty of rest
  • staying hydrated
  • using a humidifier to add moisture to the air
  • sucking on throat lozenges to soothe the throat
  • gargling with salt water
  • changing toothbrushes
  • drinking warm beverages, such as tea, lemon water, or broth

A person can reduce the risk of contracting or transmitting pharyngitis and other infections by:

  • washing hands thoroughly and regularly
  • covering the mouth and nose when coughing or sneezing
  • avoiding close contact with people who have contagious viral or bacterial infections
  • avoiding smoking and exposure to secondhand smoke
  • avoiding sharing food and drinks

Pharyngitis is rarely a serious condition and often occurs alongside colds and the flu. Viral pharyngitis typically clears up on its own within a couple of weeks, but bacterial pharyngitis may require a course of antibiotics to prevent complications.

Complications of pharyngitis, such as rheumatic fever, are rare. Anyone with severe, recurring, or persistent symptoms should see a doctor.

Practicing good hygiene and covering the mouth and nose when coughing or sneezing can help prevent getting or spreading the germs that can cause pharyngitis.