Before you apply a gel, paste or ointment, dab the mouth ulcer dry with a cotton bud, as “this will prolong the time the medication remains on the mucosa,” Dr Sellerberg recommends.

“Our experiments on animals have shown that the gel is capable of sealing and speeding up the healing process for ulcers, and it can even fill perforations in the stomach or large intestine.

Mouth ulcers, also known as canker sores ... can be applied to the sore to soothe irritation and reduce swelling. Aloe vera gel, widely recognised for its healing effects, can also be used ...