Small transparent blisters on the arms may be due to eczema, cornified rash and herpes zoster. 1. Eczema: the specific cause of the disease is still unclear, may be due to a variety of internal factors or environmental factors and the neutralization of a skin disease. Patients often manifested in the skin erythema on the basis of pimples, blisters and other symptoms. So the small transparent blisters on the arm may be caused by eczema. 2. Milia: mainly due to sweat in the stratum corneum or sweat ducts under the stratum corneum overflow caused by the patients mainly manifested as small blisters or pimples appearing on the skin, and some patients may also be accompanied by tingling or itching symptoms. Therefore, patients with white heat rash may also have transparent blisters on their arms. 3. Herpes zoster: mainly due to chickenpox – herpes zoster virus infection caused by a contagious disease, the patient is mostly manifested in the affected area of erythema, papules, cluster blisters and other symptoms, may also lead to the occurrence of transparent blisters on the arm. To summarize, there are many reasons that can cause transparent blisters on the arms of patients, and it is recommended that patients go to the hospital in time for relevant examinations to clarify the cause of the disease and early treatment.