Aphthous Ulcers - these are painful ulcers that appear in your mouth. it is a circular lesion and appears with a yellow center and a red outline on the edge of the ulcer. They are also know as Canker sores.
The reason the center is yellow is the area or tissue is dead or dying epithelial cells. The cause of this ulcer is unknown. Recurrent aphthous ulcers are referred to by patients as canker sores., A patient may have as few as one or as many as six sores at one time. Heredity, trauma, stress, food allergens, and hormonal changes are associated with the recurrence of this ulceration.
Recurrent aphthous ulcers start out as small bumps that begin with a sting. These ulcers develop on an area of unattached gingiva or mucosa (tissue) inside the cheeks, and present as a whitish dished-out area that is surrounded with a red ring. Nerve endings are exposed. Bacteria can invade the area, resulting in inflammation, and the area becomes even more uncomfortable.
Treatment: The area can be treated and the area heals quicker.