What is "dysesthesia"

n. (context medicine English) A condition caused by lesions of the nervous system that causes abnormal sensations such as burning, wetness, or itching.

Dysesthesia (dysaesthesia) comes from the Greek word "dys", meaning "not-normal" and "aesthesis", which means "sensation" (abnormal sensation). It is defined as an unpleasant, abnormal sense of touch. It often presents as pain but may also present as an inappropriate, but not discomforting, sensation. 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. Dysesthesia can include sensations in any bodily tissue, including most often the mouth, scalp, skin, or legs.

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, and the acid sensing ion channel has been shown to open at body temperature, in a model of nerve injury pain. Inappropriate, spontaneous firing in pain receptors has also been implicated as a cause of dysesthesia.

Patients suffering from dysesthesia can become incapacitated with pain, despite no apparent damage to the skin or other tissue. Patients suffering from dysesthesia also often suffer from psychological disorders.