Causes of Lip Blisters Due to the cold and dry climate, many people experience lip blisters and itchy or painful symptoms. Usually, people explain this phenomenon as “fire”. However, the fire in the mouth is not necessarily related to the climate, but is a reaction to the low immunity of the body, and is a skin disease caused by herpes simplex virus infection, medically known as herpes simplex. The way the virus gets infected The first time you get infected with herpes simplex is when you have direct or indirect contact with someone carrying the virus, such as kissing, using someone else’s utensils or lipstick. If there is some break in the mucous membrane of the skin that is visible or invisible at this time, the virus can enter and multiply from there and clinical symptoms can appear. Not all people who are exposed to the virus will develop the disease, and most people will not develop clinical symptoms if the skin mucosal barrier is intact or resistant. The manifestation of the infection After the first infection with herpes simplex, the main manifestation is the appearance of small clusters of blisters on the basis of erythema around the mouth and lips, which soon rupture to form vesicles or superficial ulcers. Although the disease may appear to have healed, the virus may still be lurking in the body. When certain factors weaken the body’s resistance, such as staying up late, overwork, mental stress, menstruation, cold, high fever or after chemotherapy, the latent virus will become active again and grow and multiply, causing recurrent herpes attacks, often in the same area. It starts with a local burning sensation, followed by clusters of small rice-grain-sized blisters, which may ulcerate in severe cases and subside on their own in about 1 week. Precautions To avoid infection or reduce recurrence, you should try to eat less spicy and stimulating food during the disease period to avoid stimulating the affected area and causing pain; keep the affected area clean to avoid secondary bacterial infection; wash your hands regularly and avoid touching other parts of your body after touching the affected area with your hands. In order to minimize the possibility of infection, it is important not to use dishes and make-up utensils that have been touched by others.