Blistering of the tongue is commonly associated with drug allergic stomatitis. The onset is usually within 24 hours after the drug is administered. The onset is sudden, often occurring on the lips, cheeks, and front of the tongue, mainly manifesting as congestion and edema of the oral mucosa, and blisters may appear, but the blisters quickly break down to form vesicles or ulcers. The lesions are irregular in shape and large in area, with many exudates on the surface, forming a grayish-yellow pseudomembrane. If the lesions occur on the lips, they may bleed and form a blackish-purple crust, which affects the opening of the mouth and causes severe pain. In addition to oral erosion, drug allergy can also occur simultaneously with skin damage, usually around the mouth and lips, lower extremities and the back of the palms of the hands and feet, mainly manifested as round erythema. There is usually an itching sensation, but the pain is not obvious. The skin around the mouth and lips is sometimes characterized by a fixed drug rash, i.e., the same lesions appear repeatedly in the same area. The first step in the treatment of drug allergic stomatitis is to immediately stop using all drugs that are suspected to cause the onset of the disease, and not to use any drugs that are not urgently needed, and to identify the type of allergenic drug as soon as possible while treating it. If you stop using allergy-causing drugs and apply anti-allergy medication, you will be cured quickly. The most common cause of small blood blisters on the tongue is local trauma, mostly from inadvertent bites on the mucosa, which may also form mucosal blood blisters, often located on the lateral edge of the tongue, which are small, 0.5 cm in size. Usually there are no obvious symptoms, no treatment is needed, usually about 1 week will be self-healing.