The first step to getting treatment for severe canker sores is to speak to a physician, recommends Mayo Clinic. A doctor may recommend mouth rinses, topical products, oral medications or cauterization. A doctor may also recommend nutritional supplements to treat the canker sores. Treatments vary if an underlying health condition is causing the canker sores.
To treat multiple canker sores, a doctor may prescribe an oral rinse that contains a steroid called dexamethasone, which alleviates pain and keeps inflammation down, notes Mayo Clinic. A mouth rinse containing lidocaine may also reduce pain.
To promote healing and keep pain at bay, a doctor may prescribe gels, creams, pastes or liquids that can be applied to the affected area, states Mayo Clinic. These topical products often contain active ingredients such as hydrogen peroxide, benzocaine or fluocinonide.
If oral rinses and topical products are ineffective, a doctor may prescribe medications that are not specifically made for canker sores but may still treat them. As a last resort, a doctor may prescribe steroids, which can cause serious side effects.
If other treatments do not work, a doctor may cauterize the canker sores using an instrument or chemicals to destroy, burn or sear the affected tissue, states Mayo Clinic. If the canker sores are related to a nutritional deficiency, a doctor may recommend nutritional supplements such as zinc, folate, vitamin B-6 or vitamin B-12.