Thank You for your time.
Oral thrush is usually due to Candidiasis.
The most common reason is a state of immunosuppression, and in MS this usually follows a course of oral or intravenous corticosteroids. It might also follow a course of potent antibiotics given for a bladder infection. It can also be observed following the use of immunosuppressants such as Cladribine. Having MS per se, does not pose an increased risk of thrush. This material is provided as general medical information only and may not include all side effects or details relevant to a particular individual's treatment.