Hepatitis C Support Group
Hepatitis C is a blood-borne viral disease which can cause liver inflammation, fibrosis, cirrhosis and liver cancer. The hepatitis C virus (HCV) is spread by blood-to-blood contact with an infected person's blood. Many people with HCV infection have no symptoms and are unaware of the need to seek treatment. Hepatitis C infects an estimated 150-200 million people worldwide.

Dry mouth and mouth ulcers
Hep C infection can cause a dry mouth. This can lead to bad breath, cracked lips, and a sore mouth and throat. It can also cause difficulty with eating and swallowing, mouth ulcers, tooth decay and tooth sensitivity. http://www.hep.org.au/index.php?article=content/about-hep/managing-hep-c-symptoms#mouth
Sjogrens Syndrome is one of many autoimmune diseases that is commonly secondary to hcv and causes dry mouth and mouth sores.
Could also be thrush or herpes... ??
http://www.medicinenet.com/lichen_planus/article.htm