Hyperalgesia

Abstract

Any injury that directly or indirectly involves the sensory nerves may lead to the development of an abnormal sensitiveness of the skin. All sensory experiences derived from the skin may be altered in this condition, so that it is frequently called a “hyperesthesia,” or a “hyperpathia.” However, since the principal alteration in sensibility is an intensification of pain sensation it is more commonly referred to as a “hyperalgesia.” In this state the tissues are unduly sensitive and they tend to react to the most innocuous stimuli with explosive sensations of pain accompanied by withdrawal reflexes. When the hyperalgesia is extreme in the causalgic states, even blowing one’s breath across the skin surface causes vivid sensations of pain and an uncontrollable impulse to jerk away from the stimulus.