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I have a big dark red blister in the mouth. What it is?
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Dr. Charles Cattano
Internal Medicine - Gastroenterology
In brief: Depends on cause
Aphthous stomatitis involving the common canker sore can occur in up to 15% of americans, and may involve some bacteria like staph epidermidis.
However, similar-appearing aphthous ulcers can be seen with herpes, crohn's disease, and other systemic disorders, if you have multiple aphthous ulcers or frequently recurring ones please have the lesions checked out.

In brief: Depends on cause
Aphthous stomatitis involving the common canker sore can occur in up to 15% of americans, and may involve some bacteria like staph epidermidis.
However, similar-appearing aphthous ulcers can be seen with herpes, crohn's disease, and other systemic disorders, if you have multiple aphthous ulcers or frequently recurring ones please have the lesions checked out.
Dr. Charles Cattano
Dr. Charles Cattano
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