Erosive blisters are herpes that rise above the skin and contain watery fluid. Blister formation is mostly the result of an inflammatory reaction, such as that caused by bacteria, viruses, parasites (scabies), or allergic reactions, and commonly includes aspergillosis, herpes-like dermatitis, and herpes zoster. Diagnostic details The lesions of aspergillosis 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, on the other hand, is a polymorphic lesion. 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 pemphigus, and itching is intense, but the mucous membranes are not damaged, and the lesions are usually found 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, in 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. Examination items: routine blood test, cytological examination of herpes virus, serological examination of herpes virus. 1. Cytologic examination: take a smear of the cells at the base of the lesion and stain it with Ritkimsa or Papanicolaou to look for large multinucleated giant cells and eosinophilic inclusions in the nucleus of multinucleated giant cells to help in the diagnosis. 2. Cytology of herpes viruses: take cells for smear, add fluorescently labeled monoclonal antibodies to HSV-1 and HSV-2, and fluorescence microscopy to find male-green fluorescent viral inclusion bodies in multinucleated giant cells can be diagnostic. 3.Herpes virus tissue culture: human embryonic fibroblasts, human amniotic cells, kidney cells, etc. are used for virus isolation and culture, and identification by immunofluorescence method can be confirmed, but the operation is complicated and expensive. 4.Electron microscopy: has a confirmatory value but is not easy to popularize. 5.Serological examination of herpes virus: detection of HSV-specific antibodies, which is of little practical value in diagnosis.