Aphthous ulcers, commonly known as canker sores, are a frequent source of oral discomfort. These non-contagious lesions develop inside the mouth, causing pain that often interferes with eating and speaking. While they can appear in various locations, understanding their characteristics and typical healing patterns provides a clearer expectation for recovery, especially when they form on the gums.
Identifying Canker Sores
Canker sores are small, shallow ulcers that form on the soft tissues inside the mouth, including the inner cheeks, tongue, soft palate, and gums. They typically appear as a round or oval lesion with a white or yellowish center and a defined red border. These lesions are not contagious and are not caused by a virus.
It is important to distinguish them from cold sores, which are caused by the highly contagious herpes simplex virus. Unlike canker sores, cold sores usually appear as a cluster of fluid-filled blisters on the outside of the mouth, often on or around the lips.
How Long Canker Sores Last
The duration of a canker sore is determined by its size and type, with most resolving on their own without specific treatment. The majority are minor aphthous ulcers, typically less than one centimeter in diameter. These minor sores cause pain for a few days and generally heal completely within seven to fourteen days without leaving a scar.
A less common type is the major aphthous ulcer, which is larger than one centimeter and deeper. These can be painful and may take two to six weeks to heal, often resulting in scarring. The rarest type is the herpetiform ulcer, which appears as clusters of tiny sores that can merge into a larger ulcer. These are not viral and usually clear up within one to two weeks. The location of the sore, such as on the gums, does not change these expected healing timelines, though continued irritation can prolong the process.
Why Canker Sores Appear
The precise cause of canker sores is not fully understood, but their development is linked to a complex interplay of factors. One common trigger is physical trauma, such as accidentally biting the cheek, injury from dental work, or aggressive tooth brushing. The use of toothpastes and mouth rinses containing sodium lauryl sulfate (SLS) has also been implicated as a potential irritant.
Certain underlying conditions and lifestyle factors contribute to their recurrence. These include periods of emotional stress, hormonal fluctuations during the menstrual cycle, and sensitivities to certain acidic or spicy foods. Nutritional deficiencies, specifically a lack of B vitamins (B12 and folate), iron, and zinc, are also associated with the appearance of these ulcers. A genetic predisposition is also a factor, as canker sores often run in families.
Managing Pain and Promoting Recovery
While canker sores heal naturally, several strategies can help manage the pain and support recovery. Rinsing the mouth with a solution of warm water and salt can soothe the pain and keep the area clean. Applying a mixture of equal parts hydrogen peroxide and water to the sore with a cotton swab, followed by dabbing milk of magnesia, is a common home remedy that may provide relief.
Over-the-counter topical treatments containing benzocaine or other numbing agents can be applied directly to the lesion for temporary pain relief. For persistent or severe sores, a healthcare provider may prescribe a medicated mouth rinse or a corticosteroid ointment to reduce inflammation and accelerate healing. Individuals should avoid irritating foods like salty, spicy, or acidic items, as these can exacerbate discomfort and slow healing.
When to Seek Professional Attention
Most canker sores resolve completely within two weeks, but professional medical attention is advised in specific circumstances. Consult a doctor or dentist if a sore is unusually large, causes extreme pain unmanaged by home care, or persists for longer than three weeks. Frequent recurrence or the presence of accompanying symptoms like a fever or difficulty swallowing also warrant an examination to rule out underlying health issues.