Mouth Sores

1 Mouth Sores Summary

Mouth sores are small, round or oval, sores that form in the mouth. They may form in any part of the mouth like the inside of lips, inside of cheeks, tongue, gums, or palate. Also called as canker sores, these mouth sores make eating and talking difficult or uncomfortable.

They are categorized into simple and complex. Simple mouth sores resolve within a week and occur 3-4 times a week. Complex mouth sores, when compared to a simple form, are less common and is more commonly found in people who had them earlier.

The sores may be white, yellow, or gray in color. These sores are usually swollen and are present singly or in groups. The sores may grow or spread to other regions. Mouth sores are painful and often cause discomfort while eating, but can be resolved with home treatment.

Mouth sores need a doctor’s visit if the ulcer persists for more than three weeks, or if one gets ulcers frequently. If the pain increases or if the sore becomes reddish, it may indicate a bacterial infection. This needs antibiotic treatment for controlling the symptom. These sores are not contagious and are more commonly found in women when compared to men.

Sores may be caused by irritation of the mouth by a sharp tooth or an ill-fitting denture. Biting cheek, tongue, and lips also may lead to irritation and mouth sores. Having hot foods or drinks may burn mouth leading to sores. Braces and chewing tobacco are also implicated in the development of these sores.

It may also be caused by:

  • Weak immune system
  • Hormonal changes
  • Nutritional deficiency
  • Stress
  • Certain medications
  • Certain medical conditions

Mouth sores are often found as an associated symptom in certain conditions like autoimmune disorders, bleeding disorders, mouth cancer, and viral infections like a hand-foot-mouth disease. Some beta-blockers, sulfa drugs, phenytoin, chemotherapy medications, and aspirin may cause mouth sores.

During the physical examination, the doctor checks the ulcer in the mouth. Medical history and other symptoms of the person are also noted. Information on exposure to certain drugs, food, and chemicals are also useful in identifying the cause of mouth sores.

The current medical conditions and risk factors may also help in diagnosing the cause of the symptom. General examination of the patient enables to find systemic disorder, if any, that might lead to mouth sores.

Skin, eyes, and genitals are also checked for the presence of sores. Other tests and investigations are based on the suspected cause of sores. Viral and bacterial cultures are suggested if the infection is the cause of sores.

Treating the underlying cause of the symptom is the main step in treating mouth sores. As a preventive measure, exposure to sore-causing foods and chemicals are avoided. Topical treatments are also suggested to control painful sores in the mouth.

Anesthetics, protective coatings, and corticosteroids are used as topical medications for controlling mouth sores. The low-power laser may be used to relieve pain and to prevent recurrence. Burning the sore with silver nitrate is another method to relieve pain caused by the sore.

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2 Causes

Mouth sores are caused by multiple factors. Physical irritation, chemical irritants, allergic reaction, systemic disease, and infections may result in mouth sores. The lining of the mouth is protected by the flow of saliva under normal conditions.

Thus, any condition that reduces the flow of saliva leads to dry mouth, a cause of mouth sores. The most common and specific cause of sores in the mouth is recurrent aphthous stomatitis, viral infections like herpes simplex and herpes zoster, other bacterial and fungal infections, injury to the mouth, chemical irritants, use of tobacco, certain medications, and systemic disorders. 

Infectious – viral infection is one of the most common causes of mouth sores. Herpes simplex virus infection causes sores on the lip, and sometimes on the palate. Known as cold sores, this is the most known form of viral infection that leads to sores in the mouth.

Other viral infections may also lead to sores. Shingles caused by varicella zoster cause ulcers on one side of the mouth. These sores often form during a flare-up of the disease. The pain caused by these sores may persist for months, even after the sores are resolved. 

Bacterial infections are also known to cause mouth sores and are often associated with swelling in the mouth. The sores may be caused by a foreign bacteria or by the excessive growth of the normal mouth-inhabiting bacteria.

Bacteria causing syphilis and gonorrhea are examples of invading bacteria that cause mouth sores. Early stages of syphilis infection are characterized by the presence of a red colored, painless sore in the mouth. Teeth and gum infections spread to other parts of the mouth, leading to abscess and sores.

Yeast Candida albicans is a normal resident of mouth which, during favorable conditions, overgrow to form cheesy, white patch on the tongue. These patches destroy the mouth lining, increasing the risk of sores.

Injury – physical injury and irritation of the lining of the mouth is a common cause of mouth sores. Accidental biting of the inside of mouth or lips causes ulcers within the mouth. Broken teeth and ill-fitting dentures may scrape the lining of the mouth causing blisters and ulcers in the mouth.

Irritation of the lining by chemicals and foods also lead to sores. Astringents, acidic foods, and certain ingredients in foods are examples of chemical irritants. Tobacco is a common irritant that leads to sores. Toxins and other chemicals present in tobacco affect the lining of the mouth and cause ulcers.

Certain medications – chemotherapy drugs are known to cause mouth sores. Some beta-blockers, sulfa drugs, phenytoin, and aspirin are also implicated in the development of ulcers in the mouth. In some rare cases, antibiotics may cause sores in the mouth. 

Systemic disorders – many diseases have mouth sores as an important symptom.

Some examples are: 

  • Behcet disease, and inflammatory condition that affects many organs like skin, eyes, joints and brain
  • Stevens-Johnson syndrome, an allergic reaction that causes mouth sores and blisters
  • Inflammatory bowel disease
  • Celiac disease, caused by intolerance to gluten in food
  • Lichen planus, a skin disease that leads to ulcers in mouth
  • Pemphigus Vulgaris, a skin disease that causes formation of blisters and ulcers in mouth

Nutritional deficiency, stress, and hormonal changes also cause sores in some people.

3 Diagnosis and Treatment

Immediate evaluation is not required for many types of mouth sores. Some of the symptoms seen along with mouth sores may indicate systemic disorders, and these need medical attention.

This includes fever, skin blisters, eye inflammation, and a weak immune system. Medical history and associated symptoms are the first steps in the diagnosis of the underlying condition.

Information on exposure to irritants including chemicals and foods, including tobacco, chemicals, metals, fumes, and toothpaste may help in identifying the possible cause of the condition.

Current medical conditions of the patient that may lead to mouth sores also are evaluated. Some conditions are known to increase the risk of this symptom, including cancer and HIV infection.

During the physical examination, the doctor may inspect and observe the location and nature of mouth sores. Other symptoms and signs of systemic disorders are also checked.

Sores and blisters in other parts of the body like eyes, genitals, and skin are also checked. Other tests and investigations are based on the possible cause of the condition.

Bacterial and viral cultures are suggested in case of persistent mouth sores. A biopsy is recommended for mouth sores that are persistent without any apparent reason.

Treating the underlying cause of the symptom is the first step in controlling mouth sores. Exposure to irritating foods and chemicals should be avoided as much as possible.

Topical treatments may also be used to alleviate pain and swelling associated with mouth sores. Antibiotics are suggested for treating bacterial infections that cause sores in the mouth.

Some common topical treatments used include anesthetics, protective coatings, and corticosteroids. Mouth rinse containing dyclonine or lidocaine is useful in reducing pain.

Lidocaine can be directly applied to the sores. This helps to numb the region, alleviating pain. Protective coatings contain sucralfate and soothe the lining. Aluminum-magnesium antacids are also used as soothing agents.

Antihistamines and lidocaine may be used in combination with these to get better relief. Corticosteroids are used only for sores caused by reasons other than infection. These are used as corticosteroid gels or corticosteroid rinse. Vitamin supplements help to reduce sores caused by deficiency.

In some cases, the low-powered laser is used to remove the sore. This is helpful in alleviating pain and to prevent recurrence of mouth sores. A small stick coated with silver nitrate is used to burn the sore. This method also helps to relieve the pain associated with sore, though it is not as effective as laser treatment.

Mouth sores resolve within few weeks with home treatment. Hot beverages and spicy foods should be avoided as it worsens the pain.

Some other steps that would be of help are:

  • Gargling with salt water
  • Eating ice pops
  • Using pain relievers
  • Applying ice to sores
  • Drink plenty of fluids

Most form of mouth sores can be prevented by: 

  • Reducing stress
  • Chewing carefully and slowly
  • Using soft toothbrushes
  • Visiting dentist to correct ill-fitting dentures and sharp tooth
  • Eat a balanced diet
  • Quit smoking
  • Limit alcohol consumption

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