Sores in or around the mouth often cause confusion due to their similar appearance. Canker sores and cold sores, however, have distinct characteristics regarding their causes, locations, and how they spread. Understanding these differences aids in proper identification and management.
Understanding Canker Sores
Canker sores, also known as aphthous ulcers, are small, shallow lesions forming on soft tissues inside the mouth. They appear as round or oval ulcers with a white or yellowish center surrounded by a red border. These sores commonly develop on the tongue, inside the cheeks or lips, the soft palate, or at the base of the gums.
Canker sores are not contagious. While their exact cause is not fully understood, various factors can trigger their development. Triggers include emotional stress, minor mouth injuries from dental work or accidental biting, and consuming acidic foods. Nutritional deficiencies, such as a lack of vitamin B-12, zinc, folate, or iron, can also contribute.
Understanding Cold Sores
Cold sores, often called fever blisters, are clusters of fluid-filled blisters that appear on or around the lips, nose, or chin. These blisters eventually break open, ooze, and then crust over. While most commonly found outside the mouth, cold sores can sometimes develop inside the mouth on the gums or roof of the mouth.
Cold sores are highly contagious, caused by the herpes simplex virus type 1 (HSV-1), though HSV-2 can also be responsible. The virus remains dormant in the body and can reactivate, leading to outbreaks. Common triggers include sun exposure, fever, other illnesses, emotional stress, and hormonal changes. Many people experience a tingling, itching, or burning sensation in the affected area a day or two before the blisters appear.
Distinguishing Them
The primary difference between canker sores and cold sores lies in their location. Canker sores develop exclusively inside the mouth, while cold sores predominantly form outside, typically on or around the lips. Canker sores are not caused by a virus and are not contagious, whereas cold sores are caused by the herpes simplex virus and are highly transmissible. This contagious nature means cold sores can spread through close personal contact like kissing or sharing utensils.
Their appearances also differ significantly. Canker sores are single, round or oval ulcers with a distinct white or yellow center and a red border. In contrast, cold sores present as a cluster of fluid-filled blisters that progress to crusting. Another distinguishing factor is the presence of preceding symptoms: cold sores often begin with a tingling, itching, or burning sensation before the blisters emerge, a symptom absent before a canker sore appears.
When to Consult a Doctor and General Care
While most canker sores and cold sores heal on their own, medical attention is sometimes advisable. Consult a doctor if a sore is unusually large, causes extreme pain, persists for more than two weeks, or recurs frequently. Also consult a doctor if sores are accompanied by a high fever, make eating or drinking difficult, or if you have a weakened immune system. For cold sores, seek advice if they appear near the eyes or if eye irritation occurs.
General care measures can help manage discomfort for both types of sores. Applying over-the-counter gels or rinses can provide pain relief. Avoiding irritants such as spicy or acidic foods or very hot beverages can prevent further irritation. Rinsing the mouth with warm salt water several times a day can help soothe the area and promote healing.