Internal mouth blisters, commonly known as mouth sores, are painful lesions that develop on the soft tissues of the mouth. These small lesions are generally non-contagious and represent a temporary disruption of the mouth’s sensitive lining. They make simple acts like eating, drinking, and speaking difficult and uncomfortable. Understanding these oral lesions and knowing how to rapidly soothe them is the first step toward finding relief. The goal of treatment is to reduce discomfort quickly and accelerate the natural healing process.
Identifying the Cause of Internal Mouth Sores
The most common type of internal mouth sore is the aphthous ulcer, often referred to as a canker sore. Although the precise cause is not fully understood, these ulcers are thought to involve a localized immune response triggered by various factors. They typically appear as round or oval lesions with a white or yellowish center surrounded by a distinct red border.
These ulcers most often form on non-keratinized, movable tissues inside the mouth, such as the inner cheeks, lips, and the floor of the mouth. Common triggers include minor physical trauma, such as accidentally biting the cheek or injury from aggressive toothbrushing or dental work. Stress and hormonal shifts, particularly during the menstrual cycle, can also precipitate an outbreak.
Dietary factors and nutritional status play a role, as sensitivities to acidic foods like citrus fruits or tomatoes can irritate the oral lining. Furthermore, a deficiency in specific micronutrients, notably vitamin B-12, folate, or iron, has been linked to recurrent sores. It is important to distinguish aphthous ulcers from intraoral herpes simplex lesions, which are caused by a virus. Herpetic sores usually present as small clusters of blisters that occur on keratinized tissue, such as the hard palate or gums, while canker sores do not.
Immediate Comfort and Home Care Methods
The immediate priority for a mouth sore is to reduce pain and protect the exposed tissue from further irritation while allowing it to heal naturally. Simple home-based rinses can offer significant symptomatic relief and are often the first-line approach for managing discomfort. One of the most accessible methods is the warm salt water rinse, which works by creating a temporary change in the oral environment.
Rinsing with a solution of half a teaspoon of salt dissolved in a cup of warm water helps to draw fluid away from the surrounding tissues through osmosis, which can diminish localized swelling. The saline solution also raises the mouth’s pH level, creating an alkaline environment that temporarily inhibits the growth of bacteria. This dual action reduces inflammation and keeps the area clean, promoting healing.
A baking soda rinse or paste offers similar benefits through its neutralizing properties. Baking soda, or sodium bicarbonate, is alkaline and works directly to balance the pH in the mouth, which can soothe the irritation caused by acids in foods or saliva. A paste made from mixing a small amount of baking soda with water can be gently dabbed directly onto the sore to reduce pain and inflammation.
Applying ice chips or small pieces of ice directly to the sore can also provide temporary numbing relief by constricting the local blood vessels, which diminishes pain signals. While the sore is active, it is beneficial to avoid foods that might mechanically or chemically irritate the exposed nerve endings. This includes spicy, highly acidic foods, and abrasive textures. Switching to a soft-bristled toothbrush and avoiding toothpastes containing sodium lauryl sulfate (SLS) can also prevent further trauma to the delicate oral mucosa.
Specialized Treatments and Professional Intervention
For sores that cause significant pain or interfere with eating, over-the-counter (OTC) topical treatments provide more targeted relief. Specialized gels and liquids containing topical anesthetics like benzocaine or lidocaine work by temporarily blocking nerve signals in the area. Applying these products directly to the lesion can provide a brief period of numbness, allowing for more comfortable eating and speaking.
It is important to note that the U.S. Food and Drug Administration (FDA) advises against the use of benzocaine products for children under two years old due to the risk of a rare, serious blood condition. Another effective OTC option is the use of protective barrier pastes or mucoadhesive patches. These products adhere to the sore and create a physical shield. This barrier protects the ulcer from contact with saliva, food, and drink, which prevents irritation and aids the healing process.
If a mouth sore is unusually large, lasts longer than two weeks without showing signs of improvement, or the outbreaks occur with extreme frequency, professional medical or dental advice should be sought. Recurring or persistent sores may indicate an underlying condition, such as a nutritional deficiency or a systemic disorder. A healthcare provider may prescribe a topical corticosteroid in a gel or mouth rinse, such as fluocinonide or dexamethasone. These anti-inflammatory agents work to suppress the localized immune response and accelerate the healing time. For severe cases where pain is debilitating, a doctor may prescribe a short course of oral steroids or a stronger analgesic rinse, such as viscous lidocaine.