Differentiating between Canker Sores and Oral Herpes.
How can you tell canker sores and oral herpes apart?
Of all of the different types of mouth ulcers that are frequently mistaken for canker sores, the most common type is the recurring intraoral herpes lesion. (The term "intraoral" simply means that the herpes lesions are "in the mouth.")
The confusion between these two types of sores doesn't have to exist. There are some very distinct differences between canker sores and oral herpes and they are easy to identify. They are:
[Use this link if you're more interested in simply how to identify canker sores.]
A) Canker sores and oral herpes form in different locations.
Intraoral herpetic lesions:
Oral herpes lesions form on firmly attached, keratinized tissues (skin). This includes: 1) The attached gingiva (the gum tissue immediately surrounding the teeth), 2) The hard palate.
Canker sores:
Canker sores form on loose, non-keratinized skin tissues of the mouth. - 1) The inside of the lips and cheeks, 2) The floor of the mouth, 3) The tip or underside of the tongue, 4) The soft palate, 5) In the region of the tonsils.
B) The early stages of canker and herpes sores look different.
Intraoral herpetic lesions:
These sores first appear as multiple, tiny vesicles (fluid-filled elevations, blisters) having a diameter on the order of 1/25 th of an inch (1mm).
Canker sores:
Typically first appear as a reddened raised area that ultimately forms into a sore that may become as large as 1/4 of an inch.
C) Ulcer shape.
Intraoral herpetic lesions:
Ruptured herpes vesicles can coalesce to form a larger sore. The borders of this combined ulceration will have a scalloped outline.
Canker sores:
As shown in the picture to the right, the ulcerated region of an aphthous ulcer is surrounded by a smooth border (rounded, regular).
D) Accompanying symptoms outside the mouth.
Intraoral herpetic lesions:
With herpes, a person may experience malaise (a vague feeling of discomfort), fever, joint pain or swollen lymph nodes in the neck.
Canker sores:
None of the above symptoms are typical for canker sores.
Evaluating mouth ulcers that are slow to heal.
When evaluating and monitoring a mouth ulcer, it's important to keep the normal time frame for canker sore healing in mind.
Canker sores can be expected to heal within a 2-week time period. Those mouth ulcers that don't heal within this time frame should be viewed with increased suspicion and be evaluated further.
Points to consider when evaluating persistent mouth ulcers.
1) Long-lasting canker sores may be associated with immunocompromised conditions (including HIV).
2) Frequent or severe canker sore outbreaks can be a symptom of an underlying, undiagnosed medical condition.
3) A persistent canker sore may need a biopsy evaluation so to differentiate it from other types of mouth lesions (including squamous cell carcinoma).
4) Any associated sources of mechanical irritation should be removed (a sharp tooth or denture edge), otherwise healing may be prolonged.
