There is a small blister in the middle of the pimple belongs to pimple herpes, which is common in pimple urticaria, eczema, chicken pox and other diseases. 1.papular urticaria:This disease is also known as insect bite dermatitis, mainly caused by mites, mosquitoes, midges, bedbugs and other insect bites or venomous sap irritation, mite bites, the skin often appear edema itchy windy pimples, pimples, ecchymosis, small blisters, blisters and other symptoms. 2. Eczema: the etiology of this disease is unknown, may be associated with chronic foci of infection, such as chronic cholecystitis, tonsillitis, intestinal parasitosis, endocrine and metabolic changes, blood circulation disorders, food factors, animal fur and other factors. Manifestation of erythema, erythema on the basis of papules, papules, severe small blisters, self-conscious intense itching and other symptoms. 3. Chickenpox:This disease is mainly caused by chickenpox-herpes zoster virus infection, manifested as red spots, papules, papules, blisters, pustules and other symptoms on the skin. It is recommended that patients according to their own situation, to the regular hospital dermatology, follow the doctor’s instructions to clarify the diagnosis, timely treatment, to avoid delaying the condition.