Mouth ulcers often begin with a
tingling or burning sensation at the site
of the future mouth ulcer.
In a few days, they often progress to
form a red spot or bump, followed by an
open ulcer.
The mouth ulcer appears as a white or
yellow oval with an inflamed red
border. Sometimes a white circle or
halo around the lesion can be observed.
The grey, white, or yellow coloured
area within the red boundary is due to
the formation of layers of fibrin, a
protein involved in the clotting of
blood.
The ulcer, which itself is often
extremely painful when touched, may be
accompanied by a painful swelling of
the lymph nodes below the jaw, which
can be mistaken for toothache.
Mouth ulcers are classified according
to the diameter of the lesion. Minor
aphthous ulcers, the most frequent
type, are less than 10 mm in diameter
and typically heal in 1-2 weeks without
scarring.
Major aphthous ulcers are greater than
10 mm in diameter and are incredibly
painful. They usually take more than a
month to heal and frequently leave a
scar.
Herpetiform ulcers are small, usually
less than 1-2 mm in diameter, and form
clusters. They typically heal in less
than a month without scarring.