Mouth ulcers, also known as canker sores or aphthous ulcers, are common, painful sores that develop inside the mouth. They typically appear on the gums, tongue, inner cheeks, or roof of the mouth, with a white or yellowish center and a red border. While most are harmless and resolve on their own, a growing ulcer can be concerning. This article explores their typical development, factors that cause enlargement, and serious underlying conditions.
Understanding Typical Ulcer Development
Mouth ulcers often arise from common triggers. Minor trauma, like accidentally biting the cheek or tongue, or irritation from dental work, harsh brushing, or ill-fitting dentures, can initiate them. Stress, anxiety, hormonal changes, or certain acidic foods can also be factors. Some individuals experience recurrent ulcers due to deficiencies in iron, vitamin B12, or folate.
Typically, a mouth ulcer begins as a small, painful spot. During the initial inflammatory phase, the body’s natural response can cause the sore to appear slightly larger, often with a red, swollen border. This is a normal part of healing as the body repairs tissue. Most minor canker sores are less than 1 centimeter across and usually heal completely within 7 to 14 days without scarring. Pain usually subsides within a few days, even if the ulcer takes longer to fully close.
Why Ulcers Might Grow Larger
While initial inflammation can make an ulcer seem to grow, persistent enlargement often indicates factors beyond normal healing. Continuous irritation or trauma, such as repeated rubbing by braces, dentures, a sharp tooth, or ongoing biting, can prevent an ulcer from shrinking. This mechanical stress disrupts healing tissue, leading to sore expansion.
An open ulcer is susceptible to secondary infections, which can enlarge it, increase pain, and delay healing. Bacterial, fungal (like oral thrush), or viral infections can colonize the site, exacerbating inflammation and tissue damage. Poor oral hygiene contributes by allowing bacterial buildup. Certain medications, such as NSAIDs, can also induce or worsen ulcers, leading to larger lesions. If triggers like acidic or spicy foods are not avoided, the ulcer may struggle to heal, maintaining or increasing its size.
Serious Causes and When to Seek Help
A mouth ulcer that grows or does not heal within a typical timeframe can indicate a serious underlying health issue. Seek medical attention if an ulcer persists for over two to three weeks, shows rapid growth, or has an unusual appearance like irregular borders, raised edges, or white/red patches. Other concerning signs include no clear cause, accompanying fever, swollen lymph nodes, difficulty swallowing or speaking, or unexplained weight loss. Multiple, recurring, or unusually large ulcers also warrant professional evaluation.
Oral cancer is a primary concern for any persistent or growing mouth ulcer. Cancerous lesions may appear as sores that do not heal, bleed easily, or grow, often on or under the tongue. Early detection is important. Certain autoimmune diseases can also manifest as recurrent, large, or unusual oral lesions. Conditions like Crohn’s disease, Behçet’s disease, or lupus can cause painful mouth ulcers as part of their systemic inflammatory response.
Severe or prolonged nutritional deficiencies, beyond typical canker sore causes, can contribute to non-healing or growing ulcers, sometimes linked to malabsorption conditions like celiac disease. Persistent viral infections, especially in individuals with compromised immune systems (e.g., HIV/AIDS or chemotherapy patients), can also lead to severe, non-healing ulcers. Less common but serious infections like syphilis or tuberculosis can also present with oral lesions that may not heal.
Medical Evaluation and Management
When a mouth ulcer is concerning, a healthcare professional, such as a dentist or doctor, will conduct a thorough evaluation. This typically involves a visual examination of the ulcer and surrounding oral tissues, along with a detailed discussion of medical history and symptoms. Various diagnostic tests might be performed to determine the underlying cause.
If cancer is suspected, a biopsy of the ulcer may be taken to analyze tissue samples for abnormal cells. Blood tests can identify nutritional deficiencies or markers for autoimmune diseases. In cases of suspected infection, a swab from the ulcer might be sent for laboratory analysis to identify bacteria, fungi, or viruses.
Treatment approaches vary widely depending on the diagnosed cause. For benign ulcers, self-care measures like avoiding triggers, maintaining good oral hygiene, and using over-the-counter pain relief or topical gels are often sufficient. If an ulcer is exacerbated by secondary infection or dental irritation, the underlying issue will be addressed, potentially with antibiotics or dental appliance adjustments. For more serious conditions, individuals are referred to specialists for specific medical treatments, including targeted therapies for autoimmune diseases or cancer. Professional diagnosis is important for any persistent or growing mouth ulcer.