What Is Pharyngitis?

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Pharyngitis is an inflammation of the pharynx (throat). The main symptom of pharyngitis is a sore, painful throat. It’s common, particularly in kids, and is typically seen in the winter, when the viruses that often cause pharyngitis are circulating.

Pharyngitis accounts for up to 5% of all visits to a primary healthcare provider. It generally isn’t serious and will go away on its own after a few days. But when the swelling is caused by things like bacteria or a fungus, medication is needed.

Man with pharyngitis holding throat and seems in pain

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Types of Pharyngitis

There are two main types of pharyngitis—infectious and noninfectious. 

  • Infectious pharyngitis is throat inflammation caused by something that’s contagious, such as a virus or bacteria (germs). 
  • Noninfectious pharyngitis is throat swelling stemming from things you can’t catch, for example, environmental influences like cigarette smoke or a digestive disorder that allows irritating stomach acid to flow back up into the throat.

Pharyngitis Symptoms

A sore throat, particularly when swallowing, is one of the hallmarks of pharyngitis. Other symptoms include:

  • Dry, scratchy throat
  • Pain when talking
  • Hoarseness

Depending on the cause of the pharyngitis, you might have other symptoms in addition to a sore throat, including:

  • Fever
  • Muscle aches
  • Nasal congestion
  • Swollen lymph nodes (glands) in the neck
  • Swollen tonsils (lymphatic organs in the back of your mouth and throat)
  • Red spots on the roof of the mouth

Causes 

Most episodes of pharyngitis are caused by viruses. But bacteria, fungi, and environmental factors can cause throat swelling and a sore throat as well.

Viruses

Eighty percent of pharyngitis cases are caused by a virus. Common culprits include:

  • Rhinoviruses: These cause the common cold.
  • Adenoviruses: These are common viruses producing cold-like symptoms.
  • Coxsackieviruses: These viruses cause a variety of infections, including the one responsible for hand, foot, and mouth disease (HFMD), a common infection in children that produces painful ulcers, typically on the palms, soles of the feet, and mouth.
  • Human parainfluenza viruses (HPIV): HPIV is a group of viruses causing respiratory illnesses. Some of those illnesses include croup (a condition mostly seen in young kids that causes swollen airways and a bark-like cough), bronchitis, and viral pneumonia.
  • Influenza (the flu): Research shows that up to 84% of people with the flu also have a sore throat.
  • Coronaviruses: These viruses cause cold-like symptoms, including sore throats. Interestingly, only about 12% of people with coronavirus, COVID-19, report having a sore throat.
  • Mononucleosis (mono): A sore throat is one of the main symptoms of mono, an infection that’s often caused by the Epstein-Barr virus.

Bacteria

A variety of bacteria can cause pharyngitis, including:

  • Group A streptococcus, a germ that commonly causes what’s known as strep throat. Group A strep infections cause up to 30% of sore throats in children and 15% in adults.
  • Haemophilus influenzae, a bacteria that can infect the epiglottis
  • Chlamydia pneumoniae
  • Mycoplasma pneumoniae, a germ that causes a milder pneumonia known as walking pneumonia
  • Arcanobacterium haemolyticum

Allergens

Cigarette smoke, air pollution, wildfire smoke, and other environmental factors can all irritate the throat and lead to pharyngitis. 

For example, one study found that 7.1% of office workers working in a total of 41 office buildings reported having a sore throat. It’s thought that poorly maintained heating and ventilation systems were to blame.

Allergies to things such as dust or pollen can also lead to pharyngitis. The nasal congestion they typically cause can make it more likely you’ll breathe with your mouth open, drying your throat. 

What’s more, the postnasal drip (mucus dripping down the back of your throat) that often accompanies allergies can cause excessive throat clearing, thereby producing a sore throat.

While a food allergy may not cause a sore throat, per se, it can lead to throat tightness and impact breathing. This is actually a sign of a life-threatening anaphylactic reaction and is a medical emergency.

Laryngopharyngeal Reflux (LPR)


LPR is a digestive condition in which stomach acids wash back up into the esophagus (a tube that connects the throat and stomach) and then into your throat and larynx (voice box). 

Those acids can irritate the throat, causing a burning sensation and soreness. LPR can be caused by weak muscles that close the esophagus from the stomach.

Fungal Infections

Infections with certain kinds of fungi can also cause your throat to swell and become irritated. 

For example, when Candida (a type of yeast that normally lives in your throat and mouth) grows unabated, it can produce an infection called thrush. Thrush appears as white patches in your mouth and down your throat that can cause pain when you swallow. 

There are a number of reasons why Candida can multiply in your mouth and throat, including:

  • Taking certain medications that cause the mouth to become dry
  • Wearing dentures
  • Having cancer or other conditions that weaken your immune system
  • Taking antibiotics (for an infection) or inhaled steroids (for asthma and other conditions)
  • Smoking
  • Having diabetes

Sexually Transmitted Infections (STIs)

When a person has unprotected oral sex with an individual living with certain STIs, the infection can settle in the throat, causing throat pain. Some of these STIs include:

Learn More: Sexually Transmitted Diseases

Diagnosis

Your healthcare provider will first do a physical exam and ask about your symptoms. They’ll be looking for things like redness in the throat, red spots on the roof of the mouth, and white patches in the mouth. 

If your healthcare provider suspects your pharyngitis is caused by Group A strep, they may perform a rapid antigen detecting test. This involves swabbing the back of your throat with a cotton-tipped applicator.

This test looks for antigens (naturally occurring substances that bring on an immune response) of Group A strep. A positive result means you have strep throat.

If the results come back negative, your healthcare provider may take another swab for a throat culture and send it to a lab.

In some cases, particularly when it’s suspected that your pharyngitis may be caused by a virus like Epstein-Barr, your healthcare provider may order blood tests.

Treatment

How a sore throat is treated depends a lot on what’s causing it.

Throat inflammation caused by bacteria, for example, needs antibiotic treatment. Pharyngitis caused by fungi needs anti-fungal medicines. And sore throats that are due to allergies may benefit from things like antihistamines and decongestants. 

However, most cases of pharyngitis are caused by viruses like the common cold, and antibiotics aren’t effective against these infections. You can get relief from over-the-counter pain medications, such as Tylenol (acetaminophen) or Advil (ibuprofen).

You can also try home remedies, such as:

  • Staying hydrated to ease throat dryness
  • Sucking on an ice pop and/or throat lozenges
  • Gargling with salt water (1/2 teaspoon salt with 1 cup of warm water) several times a day
  • Using a cool-mist humidifier

Prognosis

How long pharyngitis lasts depends a lot on what’s causing it and whether or not you’re getting treatment. Pharyngitis caused by a common cold, for example, should resolve itself without treatment in three to 10 days.

If your sore throat is caused by a bacteria like strep (symptoms can be sudden onset of the sore throat, pain when swallowing, fever, rash, and swollen lymph nodes), you can start to feel better after just a few doses of an appropriate antibiotic, such as penicillin or amoxicillin.

Regardless of the cause, healthcare providers recommend you see a healthcare provider if:

  • The sore throat is severe
  • It lasts longer than a week
  • Is recurring
  • Is accompanied by joint pain, a fever higher than 101 degrees F or an earache

Get immediate medical help if you have a sore throat and:

  • Trouble breathing or swallowing
  • Swelling in your face or neck
  • Blood in your saliva
  • Difficulty opening your mouth

Summary

Pharyngitis is the medical term for swelling in your throat that leads to a sore, tender throat. It can have a variety of causes, including viruses like the common cold and flu, bacteria such as the germ that causes strep throat, and even allergies and environmental factors. 

Treating the cause of your sore throat is the first step to alleviating the pain and inflammation. While pharyngitis caused by a virus can’t be treated with antibiotics, you can take over-the-counter pain relievers and try some self-help measures like salt water gargles.

If your healthcare provider suspects a bacteria, fungus, allergy, or digestive issue is causing your sore throat, they may suggest or prescribe certain drugs to treat those conditions, which should help the pharyngitis improve. 

A Word From Verywell

Pharyngitis is a common condition, especially in children. While it can be uncomfortable, most cases are caused by ordinary viruses and will run their course without treatment in a few days. 

Pharyngitis that isn’t caused by a virus is often caused by bacteria. These germs respond very well to antibiotics, helping you to feel better in just a matter of days.

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13 Sources
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