Paresthesia

Paresthesia refers to a burning or prickling sensation that is usually felt in the hands, arms, legs, or feet, but can also occur in other parts of the body. The sensation, which happens without warning, is usually painless and may be a sign of underlying disease.

Other Names

 * Paraesthesia (British)

Signs and Symptoms
Paresthesia has been described as feelings of:
 * Tingling
 * Numbness
 * Burning
 * Itching
 * Crawling

Causes
Chronic paresthesia is often a symptom of an underlying neurological disease or traumatic nerve damage.

Paresthesia can be caused by disorders affecting the central nervous system, such as:
 * Stroke and transient ischemic attacks (mini-strokes)
 * Multiple sclerosis
 * Transverse myelitis
 * Encephalitis

A tumor or vascular lesion pressed up against the brain or spinal cord can also cause paresthesia.

Nerve entrapment syndromes, such as carpal tunnel syndrome, can damage peripheral nerves and cause paresthesia accompanied by pain.

Certain systemic diseases can cause paresthesia. These may include:
 * Hypothyroidism
 * Alcoholism
 * Diabetes
 * Guillain-Barre syndrome
 * Multiple Sclerosis
 * Anxiety disorder or Panic disorder
 * Raynaud's Disease

Vitamin deficiency, most commonly the B vitamins, may cause paresthesia.

Medications or chemical exposure may also cause paresthesia.

Diagnosis
Diagnostic evaluation is based on determining the underlying condition causing the paresthetic sensations. An individual's medical history, physical examination, and laboratory tests are essential for the diagnosis. Physicians may order additional tests depending on the suspected cause of the paresthesia.

Treatment
The appropriate treatment for paresthesia depends on accurate diagnosis of the underlying cause.

Clinical Trials
A list of ongoing clinical trials related to paresthesia is available from ClinicalTrials.gov: paresthesia trials

Recent discoveries

 * The use of mexiletine, an anti-arrhythmic drug used to treat chronic pain, in decreasing paresthesia caused by diabetes is being studied.

Future research

 * The use of pregabalin, an antiepileptic medicine often used to treat chronic pain, is being studied as a therapy for paresthesia caused by chemotherapy for colorectal cancer.
 * A study is evaluating the use of a new medicine, BNP7787, to treat paraesthesia resulting from the chemotherapeutic agent paclitaxel (Taxol).

Expected Outcome
The prognosis for those with paresthesia depends on the severity of the sensations and the associated disorders.

Etymology
Paresthesia is from the Greek Para (alongside or altered) and esthesia (feeling).