Aphthous ulceration, commonly known as a canker sore, is a frequent and often painful condition affecting the soft tissues inside the mouth. These ulcers typically present as small, round or oval lesions with a distinct white or yellow center and a bright red border. While generally benign, their presence can cause significant discomfort, particularly when eating or speaking.
Varieties of Aphthous Ulcers
Aphthous ulcers manifest in distinct forms, each with unique characteristics related to size, depth, and healing time. The most common type, minor aphthous ulcers, accounts for approximately 80% of cases. These are typically small, measuring less than 5 to 10 millimeters in diameter, and are shallow, healing without scarring within one to two weeks. They frequently appear on the non-keratinized surfaces of the mouth, such as the inside of the lips, cheeks, or the underside of the tongue.
Major aphthous ulcers are less common, affecting about 10% of individuals, and are considerably larger, often exceeding 10 millimeters across. These ulcers are deeper, more painful, and can take an extended period, ranging from 10 to 40 days, to heal, often leaving noticeable scarring. They can develop on any area of the oral mucosa, including the roof of the mouth or the tongue’s surface. The third type, herpetiform ulcers, is relatively rare but presents as multiple, pinpoint lesions that may merge to form larger, irregularly shaped sores. Despite their name, these ulcers are not caused by the herpes virus. They typically heal within 10 days, though they can recur frequently.
Potential Causes and Triggers
The precise cause of aphthous ulcers remains unclear, but various factors can trigger their development. Minor mouth injuries, such as accidental cheek bites, vigorous tooth brushing, or irritation from dental work, are common triggers. Emotional stress is often linked to outbreaks, suggesting a psychosomatic link. Consuming certain foods, particularly those that are acidic, spicy, or abrasive, like citrus fruits, nuts, or salty snacks, can irritate the oral mucosa, leading to ulcer formation.
Underlying systemic factors also play a role. Nutritional deficiencies, such as a lack of vitamin B12, zinc, folate, or iron, have been identified as contributing factors. Hormonal shifts, such as those during the menstrual cycle, can also influence ulcer occurrence. A genetic predisposition is also recognized, with aphthous ulcers often running in families. Certain toothpastes containing sodium lauryl sulfate (SLS) have been implicated as a potential trigger.
At-Home Care and Professional Treatment
Managing the discomfort of aphthous ulcers often begins with at-home remedies. Rinsing the mouth with a solution of one teaspoon of salt dissolved in half a cup of warm water can help cleanse the area and promote drying of the sore, for 15 to 30 seconds every few hours. Over-the-counter topical anesthetic gels containing ingredients like benzocaine or lidocaine can be applied directly to the ulcer for temporary pain relief. Using an alcohol-free antimicrobial mouthwash, like chlorhexidine gluconate, may help prevent secondary infections and reduce inflammation. For more persistent or painful ulcers, a healthcare provider might prescribe stronger topical corticosteroid preparations, such as fluocinonide or hydrocortisone hemisuccinate. Mouth rinses containing dexamethasone or betamethasone sodium phosphate may also be prescribed to reduce inflammation and pain.
While many aphthous ulcers resolve on their own, professional medical or dental advice is sometimes warranted. Consult a healthcare provider if an ulcer persists for longer than two weeks without signs of healing, or if you develop unusually large or numerous sores. Extreme pain that interferes significantly with eating, drinking, or speaking also warrants professional evaluation. If canker sores are accompanied by systemic symptoms like fever, swollen lymph nodes, or general malaise, consult a healthcare provider to rule out underlying health conditions.
Aphthous Ulcers vs. Cold Sores
Aphthous ulcers are frequently confused with cold sores, but they are distinct conditions with different origins, locations, and modes of transmission. The primary distinction lies in their cause: aphthous ulcers are not caused by a virus and are not contagious.
Conversely, cold sores, also known as fever blisters, are caused by the highly contagious herpes simplex virus (HSV-1). They can be spread through direct contact, such as kissing or sharing utensils. Location is another key difference: aphthous ulcers exclusively form inside the mouth, typically on the soft, movable tissues like the cheeks, lips, or tongue. Cold sores, however, almost always appear outside the mouth, on or around the lips, though rarely inside.