Aphthous ulcers are classified according to the diameter of the lesion.
Minor ulceration :
Minor aphthous ulcers indicate that the lesion size is between 3 to 10 mm .They are most common aphthous ulcers. The appearance of the lesion is that of an erythematous halo with yellowish or grayish color.Pain that affects quality of life is the obvious characteristic of the lesion. When the ulcer is white or grayish, the ulcer will be extremely painful and the affected lip may swell. They may last about 2 weeks.
Major ulceration :
Major aphthous ulcers have the same appearance as minor ulceration, but are greater than 10 mm in diameter and are extremely painful. They usually take more than a month to heal, and frequently leave a scar. These typically develop after puberty with frequent recurrences. They occur on movable non-keratinizing oral surfaces, but the ulcer borders may extend onto keratinized surfaces. They can occur on tongue, lips and cheeks.
Herpetiform ulceration :
This is the most severe form. It occurs more frequently in females, and onset is often in adulthood. It is characterized by small, numerous, 1 to 3 mm lesions that form clusters. They typically heal in less than a month without scarring. Supportive treatment is almost always necessary.
Signs and symptoms :
Large aphthous ulcer on the lower lip. Aphthous ulcers can affect people of any age. Frequency of aphthous ulcers is reported to be more in females as compared to males. Most commonly aphthous ulcers are seen on the lining of cheeks, tongue, lips and roof of mouth. Aphthous ulcers usually begin with a tingling or burning sensation at the site of the future aphthous ulcer. In a few days, they often progress to form a red spot or bump, followed by an open ulcer.
The exact cause of many aphthous ulcers is unknown but citrus fruits (e.g., oranges and lemons), physical trauma, stress, lack of sleep, sudden weight loss, food allergies, immune system reactions and deficiencies in vitamin B12, iron, and folic acid may contribute to their development. Nicorandil and certain types of chemotherapy are also linked to aphthous ulcers.