Long blisters between the waist, may be related to mosquito bites, may also be due to contact dermatitis or shingles and other reasons. 1. Mosquito bites: often in the summer, due to more mosquitoes, especially at night when sleeping, if the skin between the waist by mosquito bites, resulting in mosquitoes in the body of the toxin retention in the skin of the bite. Insect bite dermatitis is induced, it may show the waist long blisters, may also be accompanied by obvious itching, pain symptoms. 2. Contact dermatitis: commonly found in people who are allergic to themselves, when wearing pants, if the use of belts, resulting in contact with the waist containing nickel cadmium and other metal elements of the belt buckle, may cause allergic reactions, induced by contact dermatitis, there may be a long blisters between the waist, but also may be accompanied by local skin damage, itching and other symptoms. 3. Herpes zoster: usually caused by varicella zoster virus infection, can lead to waist blisters, usually unilateral distribution, accompanied by pain, fever and other symptoms. The blisters on the waist may also be caused by other reasons. If the symptoms are serious, you should seek medical advice as soon as possible to diagnose the causative factors and then be guided by a doctor for treatment.