I've had this before and was told by Dr. it was due to lack of Vitamin B-2 or Riboflavin. I took B-Complex and within a few weeks the lesion went away.
Lack of Vitamin B12 can appear as cracks and sores in the corners of your lips.
You may also have a fungal infection now too. Go back to your doctor so that he can check your blood for any deficiency and also prescribe an antifungal/antibacterial cream for you to use.
Make sure that you have a healthy and well balanced diet with plenty of fresh fruit and vegetables. Eat natural live yogurt and drink plenty of water. Avoid or cut down on sugary foods and processed foods. Vitamin B12 is in breakfast cereals, meat, nuts and legumes.
Don't take part in oral sex.
It could be an allergic reaction. How long have you been using it? I would suggest you to go to the doctor who prescribed it to you so you could have them see what the problem is.
Hi! Ive only gotten that once but in a desperate search to make it stop I applied antifungal otc cream several times a day and before sleeping AND took Womens One a Day Fitness vitamins. It went away within a few days and never came back, The underlying cause might be a vitamin deficit?