Erosive blisters are blisters that rise above the skin and contain fluid. It extends and expands to the periphery. It is usually the result of an inflammatory reaction. Etiology Most blister formation is the result of an inflammatory reaction, such as bacterial, viral, parasitic (scabies), or inflammation caused by a metabolic reaction, commonly known as pemphigus, herpes-like dermatitis, and herpes zoster. Diagnosis The lesions of pemphigus are characterized by large blisters on normal-looking skin and mucous membranes with epidermal peeling, which occur in the folds of the skin and are most often seen in middle-aged people with the disease. Herpes herpetiformis, and herpes zoster are polymorphic lesions. Differentiation Erosive blistering polymorphic lesions refer to the variety of rash patterns. For example, in herpes-like dermatitis, in addition to blisters, there are various kinds of damage such as erythema, papules, and windblasts, and intense itching, but the mucous membranes are not damaged, and the lesions tend to occur in the axillae, shoulders, and arms. Another example is chickenpox, which starts as a papule, then blisters, oval-shaped, and finally crusts and flakes, characterized by the presence of various stages of rash, i.e., papules, herpes, and crusts at the same time, with a centripetal distribution, more on the trunk than on the extremities. Herpes zoster is a type of herpes caused by the varicella virus. The lesions are characterized by clusters of blisters distributed in bands along the peripheral nerves on one side of the body, accompanied by neuralgia and local lymph node enlargement. Generally, herpes zoster is immune for life, meaning that recurrences are rare after healing. Advanced visceral cancers also present with herpes zoster, but they are recurrent and systemically disseminated, so it is especially important to be aware of this situation. It has been observed that when herpes zoster is present in cancer, the patient mostly dies within six months. Polymorphic lesions are also seen in systemic lupus erythematosus, where erythema, papules, blisters, petechiae, vesicles and ulcers can be seen, while butterfly-shaped erythema on the face is its characteristic feature. Prevention With the advent of summer, part of people’s skin is exposed and they may be burned by boiling water, oil, chemicals, etc. if they are not careful. To deal with blisters after burns, you can first drain the water in the blisters from a low level, and then rinse the wound with natural water for more than half an hour. After a burn, one should use a sterilized pinhole, scissors, etc., to poke the blister from the low side of the blister and release the water inside, because the blister is rich in inflammatory substances that can easily cause infection. However, when draining the blister, one must also be careful not to break the skin outside the blister, because the intact skin is the human body’s barrier against bacterial invasion, and once it is broken, the bacteria will quickly invade and infection will occur.