Last updated: Thu, Jun 22, 2017
Secondary punctate hyperalgesia lasts more than twelve hours. The amount of pain from a controlled punctate stimulus is uniform across the area of punctate hyperalgesia and falls off rapidly at the edge. All of this indicates that there is a different mechanism for secondary stroking hyperalgesia than for secondary punctate hyperalgesia.
Secondary punctate hyperalgesia appears to result from increased sensitivity to the input of A-delta fibers. Since A-delta fibers have no heat receptors, this explains why there is no secondary hyperalgesia to heat.