Similarly deficiencies in vitamin B12, zinc have been linked to oral ulceration.

Persons with certain systemic diseases may be prone to oral ulceration, but this is secondary to the underlying medical condition.

Resolution of the systemic condition often leads to a decreased frequency and severity of the oral ulceration.

A systemic cause is more likely in adults who suddenly develop recurrent oral ulceration with no prior history.

Special investigations may be indicated to rule out other causes of oral ulceration.

A rare side effect of use of dried pancreatic extracts is oral ulceration and bleeding.

Antibodies to α-gliadin have been significantly increased in non-celiacs individuals with oral ulceration.

Many infections can cause oral ulceration (see table).

However, the epithelia of the mouth also has a high turnover rate and makes oral ulceration a common side effect of chemotherapy.

Autoimmunity is also a cause of oral ulceration.