Canker sores are common mouth ulcers that are not sexually transmitted diseases (STDs). They are not contagious and cannot be spread through intimate contact.
What Are Canker Sores?
Canker sores, also known as aphthous ulcers, are small, shallow lesions that develop on the soft tissues inside the mouth. They typically appear as round or oval sores with a white or yellowish center surrounded by a red border. These painful ulcers can form on the tongue, inside the cheeks or lips, on the soft palate, or at the base of the gums. Most canker sores are relatively small, often less than a centimeter in diameter, and usually heal on their own within one to two weeks without scarring. Some individuals may experience recurring canker sores throughout their lives.
Understanding the Distinction: Canker Sores vs. STDs
Canker sores are not sexually transmitted because they are not caused by a pathogen transmitted through sexual contact. This distinguishes them from oral lesions that can be symptoms of STDs, which involve infectious agents.
For instance, oral herpes, caused by the herpes simplex virus (HSV-1 or HSV-2), presents as fluid-filled blisters that typically appear outside the mouth, often on or around the lips, though they can sometimes occur inside the mouth. Unlike canker sores, herpes lesions are highly contagious and can spread through direct contact, including kissing or oral sex. Herpes blisters usually crust over as they heal, a different pattern from canker sores.
Syphilis, a bacterial STD, can manifest as a chancre, a firm, typically painless sore, during its primary stage. These chancres can appear in the mouth, on the lips, tongue, gums, or near the tonsils. While they may resemble ulcers, a key difference is their often painless nature compared to the significant pain associated with canker sores. Chancres are highly contagious and are a direct sign of a bacterial infection that requires medical treatment.
Gonococcal pharyngitis, caused by the bacterium Neisseria gonorrhoeae, is a throat infection that can result from oral sexual contact. While it may cause a sore throat, swollen lymph nodes, or occasionally white spots, these symptoms are generally part of a broader infection and do not typically present as distinct, well-defined ulcers akin to canker sores.
Common Causes and Triggers of Canker Sores
The precise cause of canker sores is often unknown, but various non-infectious factors can trigger their development. Minor injuries to the mouth are common, such as accidental cheek biting, aggressive tooth brushing, or irritation from dental work or braces. Certain foods can also act as triggers, particularly acidic or spicy items like citrus fruits, tomatoes, or some nuts.
Nutritional deficiencies, including low levels of iron, vitamin B12, folate, or zinc, have been linked to canker sore formation. Stress is another frequently cited factor, with emotional stress potentially contributing to outbreaks. Hormonal shifts, such as those during menstruation, can also increase susceptibility. Additionally, certain toothpastes and mouth rinses containing sodium lauryl sulfate (SLS) may irritate the mouth lining and trigger sores in sensitive individuals.
When to Seek Medical Attention for Oral Sores
While most canker sores are harmless and resolve on their own, certain signs indicate that medical attention is appropriate. Consult a healthcare professional if you experience unusually large sores or if new sores appear before old ones have healed, indicating frequent recurrence. Sores that persist for more than two weeks without showing signs of healing also warrant evaluation.
Extreme pain that interferes with eating or drinking, or sores accompanied by fever or other systemic symptoms like diarrhea or swollen lymph nodes, suggest a need for medical assessment. If an oral sore extends onto the lips or is painless, it should also be examined to rule out other conditions. For typical canker sores, self-care measures like avoiding triggers and using over-the-counter pain relief can help manage discomfort until they heal.