Canker Sore And How It Is Different From Strep Throat

Canker sores and strep throat affect adults and children. Both conditions can be painful, but there are significant differences between them. 

Understanding their differences is crucial in implementing the correct prevention measures and properly managing signs and symptoms. Here's a canker sore and strep throat comparison to identify how the two differ.  

Have you considered clinical trials for Strep throat?

We make it easy for you to participate in a clinical trial for Strep throat, and get access to the latest treatments not yet widely available - and be a part of finding a cure.

What is a canker sore? 

A canker sore is a noninfectious condition with an unknown cause. It causes a painful ulcer with a red border inside your mouth. This condition is also referred to as an aphthous ulcer and affects children and adults. 

Although the exact cause is unknown, aphthous ulcers are known to run in families, and vitamin/mineral deficiencies, some foods, trauma to the mouth, and emotional stress can all be factors for development.

Currently, canker sores have no prevention outside of avoiding triggers to prevent them from returning after disappearing. But there are medical solutions to manage the condition. 

What is strep throat? 

Strep throat refers to the infection of the throat and tonsils (tonsillopharyngitis) by group A beta-hemolytic streptococcus (GABHS). Strep throat is contagious, unlike a non-contagious canker sore. The infection is caused by group A Streptococcus bacteria that spread through infected respiratory droplets,¹ skin sores, and surfaces. 

Strep throat manifests typically within 2–5 days.² Additionally, not everyone with the GABHS bacteria develops strep throat. Some people are termed carriers and chronically colonized by GABHS asymptomatically.

Signs and symptoms of canker sores vs. strep throat

Anyone can get a canker sore, children and adults alike. Common signs and symptoms of canker sores include: 

  • Well-demarcated, yellow or white circular ulcers with red edges:  The sores usually appear on the mouth floor, the lip, the lower surface of the tongue, and the cheek inside the mouth.  

  • Slight pain or burning sensation in the mouth: This may happen before the ulcers form. 

On the other hand, strep throat is unpredictable. Symptoms may manifest in some people, while others can be asymptomatic carriers. 

While the infection can affect anyone, it's less common in adults and more common in children between 5–15 years. Common signs and symptoms of strep throat include: 

  • Sore throat: You experience pain in the throat, especially when swallowing, that can extend up to the ears.

  • Red, swollen tonsils: Sometimes, the tonsils may have white marks or patches of pus. 

  • Inflamed lymph nodes: Lymph nodes in the front of the neck may swell. 

In addition to the symptoms above, fever and pain not accompanied by coughing and a runny nose may signify strep throat. In children, additional symptoms of strep throat may include nausea and stomach pains. 

Diagnosing canker sores and strep throat

Can strep look like canker sores? You can easily tell the difference between the two based on the areas they affect and how they manifest. 

Canker sores affect the lining of the mouth, usually the tongue, cheek, and lip. They appear as round, white or yellow ulcers with red edges. Minor canker sores have diameters smaller than 1cm and heal within 1–2 weeks. Major canker sores may be bigger and deeper and might take several weeks or months to heal. 

On the other hand, strep throat affects the throat and tonsils. However, you can't diagnose it using symptoms alone — you should visit a doctor for an advanced diagnosis. A throat culture is the most thorough test for strep throat. 

Throat culture tests are necessary when diagnosing strep throat in children and teenagers because they may get rheumatic fever³ if the infection is left untreated. Rheumatic fever can affect the heart, joints, and nervous system. 

Treating canker sores and strep throat

Canker sores can disappear without treatment. While there's no specific medication (yet) to treat or prevent canker sores, you can manage the condition with various topical gels and sometimes vitamin supplements.

On the other hand, you can use prescribed antibiotics to treat strep throat. They will kill the bacteria causing the infection and prevent rheumatic fever.

Preventing canker sores and strep throat

Canker sores are not contagious, so preventing recurrence is easy: 

  • Maintain good oral hygiene and avoid oral hygiene products that may trigger your sores

  • Avoid emotional stress

  • Use dietary supplements if you have nutrient deficiencies

  • Avoid foods that may be triggers for you

Strep throat is contagious. Practicing good hygiene can help prevent catching the infection. Ensure communal areas such as classrooms are well ventilated and avoid using items an infected individual has used. Additionally, using prescribed antibiotics helps prevent infecting others with strep throat. 

When to see a doctor

See a health provider if canker sores are recurring or causing eating difficulties. You should also talk to a doctor if the condition is exacerbated by a deficiency of vitamins or minerals.

Whenever you suspect you have strep throat, it's best to see a doctor so they can diagnose you. Talking to a doctor ensures you use the proper medications to reduce the risks of complications. 

The lowdown

Strep throat is contagious, while a canker sore isn't. Both cause pain and can affect anyone, but they manifest differently with distinct signs and symptoms. Canker sores cause white or yellow ulcers inside the mouth, while strep throat causes sore throat and swollen tonsils.

  1. Annex C respiratory droplets (2009)

  2. Pharyngitis (Strep throat) | Centers for Disease Control and Prevention

  3. Rheumatic fever: All you need to know | Centers for Disease Control and Prevention

Other sources:

Have you considered clinical trials for Strep throat?

We make it easy for you to participate in a clinical trial for Strep throat, and get access to the latest treatments not yet widely available - and be a part of finding a cure.

Discover which clinical trials you are eligible for

Do you want to know if there are any Strep throat clinical trials you might be eligible for?
Have you taken medication for Strep throat?
Have you been diagnosed with Strep throat?

Editor’s picks