Sucking blister. The oval blister pictured here was present at birth and is a result of normal sucking behavior in utero. Sucking blisters are fairly common and are usually located on the forearm, wrist, or hand. They are most often solitary and involve only one upper extremity. However, lesions involving both hands, or even involving a foot, are sometimes seen. The sucking blister resolves spontaneously as soon as bottle or breast is offered as a dietary substitute.