Canker sores are common oral lesions that cause pain and irritation within the mouth. Understanding the distinct nature of canker sores is important for effective management.
Understanding Canker Sores
Canker sores, also known as aphthous ulcers, are small, shallow lesions that develop on the soft tissues inside the mouth or at the base of the gums. They typically appear as round or oval sores with a white or yellowish center and a distinct red border. These ulcers can form on the tongue, inside the cheeks or lips, on the roof of the mouth, or under the tongue. While their exact cause is not always clear, factors such as emotional stress, minor injuries to the mouth, nutritional deficiencies, and sensitivities to certain foods can trigger their appearance. Canker sores are not contagious and usually resolve on their own within one to two weeks, although they can be quite painful, making eating and talking difficult.
Understanding Acyclovir
Acyclovir is an antiviral medication primarily used to treat infections caused by certain viruses. It works by interfering with the replication process of viral DNA. Acyclovir is effective against various herpesviruses, including herpes simplex virus (HSV) types 1 and 2, which cause cold sores and genital herpes, and varicella-zoster virus (VZV), responsible for chickenpox and shingles. The medication is converted into an active form by an enzyme found only in virus-infected cells, which then inhibits the viral DNA polymerase, preventing the virus from multiplying. This targeted action makes acyclovir a specific treatment for viral infections.
Canker Sores Versus Cold Sores
A common source of confusion arises from the similar appearance and discomfort associated with canker sores and cold sores. However, these two types of oral lesions have fundamentally different causes. Cold sores, often called fever blisters, are caused by the herpes simplex virus (HSV) and are highly contagious. They typically appear on or around the lips, though they can also form on other facial areas.
In contrast, canker sores are not caused by a virus and are not contagious. They almost always develop inside the mouth on soft tissues. Because acyclovir specifically targets viral infections by inhibiting viral replication, it is ineffective against canker sores.
Treatments for Canker Sores
Since acyclovir is not effective for canker sores, treatment focuses on managing symptoms and promoting healing. Over-the-counter options include topical anesthetics containing ingredients like benzocaine or lidocaine, which can numb the area and provide pain relief. Oral rinses can also be beneficial, such as those made with salt water or baking soda, which help to keep the area clean and reduce irritation.
Some commercial mouthwashes, including those with chlorhexidine, can also help prevent germ growth and inflammation. Avoiding trigger foods, particularly acidic, spicy, or abrasive items, can prevent further irritation and discomfort. Maintaining good oral hygiene, using a soft-bristled toothbrush, also supports the healing process. For more severe or persistent canker sores, healthcare professionals may prescribe stronger medications, such as corticosteroid rinses or gels, to reduce inflammation and pain. In some cases, nutritional supplements may be recommended if deficiencies are a contributing factor.