Is It a Canker Sore or Something Else?

Canker sores are lesions that may form on the gums or the soft tissues of the mouth. Canker sores often range in color from white to yellow with a red border and have a diameter of less than 1 millimeter. Lesions of this kind are rather prevalent. Canker sores are common, but you shouldn't automatically assume that any sore in or around your mouth is one. According to Chirag Shah, MD, cofounder of Accesa Labs, a website that facilitates affordable medical lab testing, there are a number of conditions that can look like a canker sore but actually represent something more serious. Can't put your finger on that white thing in your mouth. Here are several medical issues that can have you thinking you have a canker sore instead.

Herpes Zoster

It's possible that the sore on your mouth is a cold sore and not a canker sore. Cold sores, which are painful blisters with features similar to canker sores, are also known as fever blisters. However, a New York City prosthodontist, Samantha Rawdin, DMD, says that canker sores are distinct from cold sores, which are caused by the herpes simplex virus (HSV-1), since they are not communicable and do not develop on the keratinized tissues of the oral region (such as your lips). Some individuals get cold sores after being kissed or eating or drinking from an infected person. Even though cold sores are unattractive, there is good news: they normally cure in approximately two to four weeks, although they may reoccur.


These lesions, which manifest as white spots or patches within the mouth, may easily be mistaken for canker sores. Unlike canker sores, leukoplakia patches don't cause any discomfort. Some areas of this ailment are benign, like a canker sore, whereas others may develop into malignancy. Depending on the size, shape, and appearance of the abnormal cells, anywhere from 3 to 17.5 percent of patients with leukoplakia may progress to squamous cell carcinoma. Since early treatment and diagnosis might lessen the risk, your doctor may suggest a biopsy to rule out cancer if you have this illness.


In most cases, a canker sore heals on its own within a week or two. Dr. Shah advises seeking medical attention if a canker sore lasts longer than two weeks, worsens in size, or causes worry. Inside the mouth, a white or red area, called an erythroplakia, may indicate a sore that won't heal. However, these growths are more dangerous since they may eventually develop into cancer. Squamous cell carcinoma develops in around 50% of these lesions. Erythroplakia's origin is uncertain, however it has been connected to tobacco usage.

Planus Lichenoides

Instead of a canker sore, you may have lichen planus if you have a painful white patch that also itches. Spots on the face are occasionally joined by a white, lace-like patch on the inside of the cheeks. One intriguing aspect of this illness is that it manifests in places other than the mouth itself. Itchy lumps or patches may appear anywhere on the body if you have lichen planus. This inflammatory disorder is characterized by the aberrant immune response that targets skin and mucous membrane cells.

Throat Illness

Sometimes termed "oral candidiasis," "oral thrush" is a fungal infection that manifests as white spots within the mouth. Pain, a burning feeling, bleeding gums, and trouble swallowing are all symptoms of this illness. An impaired immune system is frequently the cause of oral thrush, which is caused by the fast multiplication of yeast in the mouth. This might occur if you're using immunosuppressant drugs or have just finished a round of antibiotics.

Cancer of the Mouth or Mouth Structure

See a doctor or dentist if a sore doesn't heal in a couple of weeks, or if it becomes worse. It's possible that the mouth sore you have is indeed cancer. Tiny white sores within the mouth are another symptom of oral cancer. Such lesions tend to thicken and cause discomfort over time. Oral cancer may spread to the lymph nodes and other regions of the body if not caught early. Remember that although canker sores often appear on the soft palate within the mouth, the hard palate and the tongue are also at risk for developing oral cancer. If you also have other symptoms, including a fever, throat numbness, or hoarseness, or if you have a history of smoking or other tobacco use, your sore might be oral cancer. A lesion biopsy may confirm or refute the presence of malignancy. If the results of the tests indicate that you have cancer, your doctor will order imaging tests (such as an MRI or CT scan) to check for metastases.


Cold sore virus (HSV-1) is the same herpes virus that may cause an infected person to have a painful infection of the lips and gums. Although anybody may get herpes simplex virus type 1 (HSV-1), most people's first experience with the virus comes in the form of childhood gingivostomatitis. Before the age of 50, almost 90% of the population will have been exposed to the HSV-1 virus. Gingivostomatitis is common, but not universal, and cold sores are not always the outcome. Gingivostomatitis is characterized by the appearance of a little red or white sore on the soft palate, gums, or inside of the cheek, much like a canker sore. However, unlike a canker sore, this ailment can also result in a high temperature and bleeding gums. In addition, bad breath is a frequent symptom. These blisters are short-lived and usually disappear within a few weeks even without therapy. However, if given within 72 to 96 hours after the commencement of symptoms, an oral antiviral such as acyclovir (Zovirax) may reduce the length of the sores.

Never Ignore Persistent Mouth Sores

An individual mouth ulcer is most likely a canker sore, which is not dangerous and will heal on its own in a few days. Keep a tight check on the lesion, however. If it persists or worsens in size, it might be a sign of something more severe. The sooner you get in to visit a doctor or dentist for an evaluation, the better. If the lesion is precancerous or malignant, catching it early increases the likelihood of a successful outcome with prompt treatment.

Updated on: 23-Feb-2023


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