Rash inside my mouth?

Dear doctor,

I have a rash inside my mouth that is rather painful. I am 15 years old and about 3 weeks abo had to go to the dentists where they pulled a tooth. I was at the orthodontists today and they said it may have been from the numbing shot they gave me at the dentists. It is painful and has something that looks like a canker sore in it (all white and whatnot) and lots of little red and kinda white bumps. It is in the general area of the shot but why would it show up 3 weeks later? No one has really looked at it yet or took me seriously, but it is very painful and sorta looks like pictures of herpes online. I also have a few canker sores in my mouth, which I usually only get maybe 2 a year. The other thing they say may be causing it is that after I went to the dentists, I started brushing much more and harder than usual, although the affected area isnt really where is brush, it is in the back of my mouth on the side of where the wisdom teeth will come it. It hurts and I am scared it could be herpes. I had intercourse a year and a half ago, if that helps and havent really kissed since. If you dont know please ask someone who does.


Thank You Very Much.

[Bhupinder Kaur, MD]

Hello,
From the symptoms it sounds like canker sores. Herpes sores present outside the mouth and rarely inside the mouth. Canker sores are generally caused by  stress, tissue injury, eating certain foods – including citrus or acidic fruits and vegetables or underlying health condition, such as an impaired immune system; nutritional problems, such as vitamin B-12, zinc, folic acid, or iron deficiency; and gastrointestinal tract disease, such as Celiac disease and Crohn's disease.

Pain from a canker sore generally lessens in a few days and the sores usually heal without treatment in about a week or two. Avoid spicy or acidic foods during this time. You can use topical ointments like numbing ointments, such as benzocaine (Oragel), anti-inflammatory (steroid) gels, Benadryl allergy liquid mouthwash, oral preparations of steroids and vitamin supplements.

But if the sores last for more than 3 wks or start spreading then please consult a dermatologist.

Hope it helps. Take care and please do keep me posted on how you are doing or if you have any additional queries. Kind regards.