Mouth ulcers can be caused by a number of factors, including:

• Physical injury to the area (e.g. biting the inside of the cheek, having a sharp edge on a tooth, eating sharp or rough foods, wearing braces or dentures that rub, burning the mouth when eating or drinking, brushing the teeth too vigorously)
• Hypersensitivity to certain food and drinks, such as coffee, chocolate and foods containing gluten and peanuts
• Stress and/or anxiety
• Infection
• Vitamin deficiency (particularly B12 or iron)
• Hormone changes (e.g. during pregnancy)
• Medical conditions or medical treatments (such as coeliac disease).

You may find when discussing mouth ulcers with customers that they have been feeling run down lately, as this can be a contributing factor.

Cold sores are caused by the herpes simplex virus and are contagious. About 70 per cent of the adult population are infected with the virus but only a quarter suffer regularly from cold sores. A cold sore can be passed on through close contact (e.g. kissing) or sharing cutlery but they are not a result of having a cold. The infection lies dormant until it is triggered by: an illness, hormone changes around the menstrual cycle, or sunshine (wearing lip sunblock can help to prevent this).

Important

People affected with a cold sore should not kiss babies. It can lead to neonatal herpes, which is very dangerous.