Dysesthesia (dysaesthesia) comes from the Greek word "dys", meaning "not-normal" and "aesthesis", which means "sensation" (abnormal sensation).[1] It is defined as an unpleasant, abnormal sense of touch, and it may be, or not be, considered as a kind of pain.[2] It is caused by lesions of the nervous system, peripheral or central, and it involves sensations, whether spontaneous or evoked, such as burning, wetness, itching, electric shock, and pins and needles.
It is sometimes described as feeling like acid under the skin. Burning dysesthesia might accurately reflect an acidotic state in the synapses and perineural space. Some ion channels will open to a low pH, the acid sensing ion channel has been shown to open at body temperature, in a model of nerve injury pain. Dysesthetic burning may be hallucinatory as to the cutaneous surface, but accurate as to what is occurring in the synapses.
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A patient suffering from dysesthesia can find it to be unbearable at times. Dysesthetic burning has been called "Dante-esque" pain. The terminology used to describe it is usually interchangeable with descriptions of Hell in classic literature. It is the "bluntest" pain of which the human body is capable, and is characterized by the absence of accurate discriminative information.
Temperature change and heat both affect the sensation and raise the level of the steady pain. This pain upgrades with tonic light touch, phasic rubbing, or rough textures to become evoked pain.
The patient often cannot endure the touch of clothing. His or her entire life becomes an exercise in avoiding evoked pain. It causes difficulty in obtaining rest because bed-clothing contacts the skin. It drives the patient to a hysterical search for relief of the pain, which ends in some degree of resignation and frequent depression. Patients indicate that it has robbed them of their identity, since their values and mental priorities are so consumed by its avoidance.[4]