Peripheral neuropathy describes damage or symptoms in the sensory nerves at the peripheries of the body, generally those in the skin, but including the tongue and mouth. A neuropathy can exhibit itself as either a lack of sensation (such as numbness or trembling) or a sensation that isn't there (such as, tingling, the sensation of "pins and needles", pain, an itch or burning). 

Intermittent short term local peripheral neuropathies (such as having a leg fall asleep) are common and usually aren't cause for concern. However, widespread, sudden and chronic neuropathies are generally a symptom of an underlying illness. Unfortunately, neuropathy is a very non-specific symptom common to many diseases, and even the type of sensation is not of much help in a differential diagnosis. More important is whether the sensation is generalized, focussed, has a focus in several areas, or is symmetrical. 

Some of the causes are genetic diseases, metabolic diseases, toxins, including certain drugs such as flouroquinolone, inflammatory and autoimmune diseases and trauma.

Peripheral neuropathy can be very serious. In severe cases, the patient cannot stand any contact with the skin, even to the point of not being able to wear clothing or have a bedsheet draped over them.   

Peripheral neuropathy at Wikipedia

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