Dysesthesia: causes, particular symptoms and treatments for loss of sensitivity

 Since dysesthesia is a common symptom of multiple sclerosis, it is important to recognize it so that you can quickly consult a doctor if you are unsure. According to the Academy of Medicine, dysesthesia is characterized by an "unpleasant subjective sensation perceived in a skin territory, without contact with an external object." This means that it causes sensations of pain in the absence of a stimulus.

1. Dysesthesia: definition

There are different types of dysesthesia:

• Scalp dysesthesia, also known as burning scalp syndrome, involves pain, burning, tingling, or itching on or under the scalp. There is usually no rash, scaling, or other visible irritation. A 2013 study published by the American Medical Association suggests that scalp dysesthesia may be related to cervical spine disease.
• Skin dysesthesia is characterized by a feeling of discomfort when the skin is touched, whether it is clothing or just the light wind blowing.
• Occlusal dysesthesia is discomfort in the mouth when biting, usually with no obvious cause. Researchers initially thought occlusal dysesthesia was a psychological disorder. But a 2017 case study published on the U.S. National Library of Medicine website suggests that it may be associated with misalignment of the teeth in the lower and upper jaws, resulting in an imbalance during the bite.

Dysesthesia must be differentiated from paresthesia and hyperalgesia, which are also common symptoms of multiple sclerosis:

• paresthesia is manifested by sensory symptoms such as numbness, tingling, "goosebumps" or a "tingling" sensation. These sensations are uncomfortable, but are not usually considered painful;
• Hyperalgesia is an increased sensitivity to painful stimuli.
• Dysesthesia is, therefore, more severe than paresthesia and is not the result of a reaction to an apparent stimulus.

2. Symptoms of dysesthesia

Symptoms of dysesthesia often include sensations, such as:

• pain or tightness;
• tingling of the skin;
• burning or stinging;
• sharp, stabbing, or tearing pain;
• sensations similar to an electric shock.

It usually occurs in the limbs but can affect any part of the body. Pain due to dysesthesia is either acute or chronic. Acute pain comes on suddenly and goes away quickly, while chronic pain can also come on suddenly but lasts for a long time. When a person has dysesthesia, he or she may go quickly from a normal sensation to an abnormal sensation. For example, the sensation of clothing against the skin may suddenly become very painful, even unbearable.

3. Causes of dysesthesia

The pain and strange sensations associated with dysesthesia may be due to damage to the sensory nerves. Incorrect signals from the nerves can cause the brain to simulate strange sensations. For example, if you have dysesthesia, you may experience painful sensations in your leg even though there is nothing wrong with it. This is actually a communication problem between the brain and the nerves in the leg, which causes a painful response without any real cause. However, the pain is real.

In terms of primary causes, multiple sclerosis is often responsible for dysesthesia. According to the National Multiple Sclerosis Society, more than half of people with multiple sclerosis report pain as a major symptom of their disease. And about 1 in 5 people who report stabbing pain describe it as a burning pain that primarily affects the legs and feet. However, the symptoms caused by dysesthesia may be completely unrelated to multiple sclerosis and may be due to injury, trauma, or another underlying condition, including:

• diabetes, due to nerve damage caused by chronically high glucose levels;
• Guillain-Barré syndrome is a rare neurological condition in which the immune system attacks and damages part of the peripheral nervous system;
• Lyme disease, which can cause neurological symptoms similar to multiple sclerosis, including itching and burning;
• HIV (human immunodeficiency virus, which causes AIDS), because of the resulting sensory and motor peripheral nerve disorders;
• Shingles, when tingling and pain occur near the lesions;
• surgery that has resulted in nerve damage, as is often the case in dental surgery;
• phantom limb syndrome following an amputation;
• a herniated disc that creates compression;
• a cancerous tumor, which can cause compression, but also neuropathic and nociceptive pain.

Dysesthesia can also be caused by medication: chemotherapy or treatment for tuberculosis.

4. Dysesthesia: when to consult?

If the symptoms due to dysesthesia handicap you in your daily life, it is recommended to consult your doctor, who will refer you to a neurologist. Indeed, the primary causes of the pain must be diagnosed and treated if necessary. However, dysesthesia does not always require treatment. In addition to the fact that dysesthesia can be a sign of serious pathology, it is important to consult a doctor, because complications can occur in the case of persistent dysesthesia, for example:

• irritation of the skin or scalp, as the person sometimes scratches himself or herself until he or she bleeds;
• Fatigue, due to the lack of restful sleep caused by chronic pain;
• irritability, due to the pain and lack of sleep;
• anxiety, due to the lack of certainty about the causes of the pain;
• depression and social isolation, due to the pain and lack of desire to protect oneself.

5. Examination and diagnosis of dysesthesia

The general practitioner takes into account the description of the symptoms and examines the patient to try to determine the primary cause of the dysesthesia. He questions his patient to know if he is taking medication that could explain the dysesthesia. Depending on the location of the pain, he refers the patient to a dermatologist or neurologist. He also prescribes blood tests to determine if the person suffering from dysesthesia is a carrier of Lyme disease or HIV. Additional tests are then considered, including:

• an electromyogram, to assess damage to the nervous system;
• an X-ray, a CT scan, or an MRI (magnetic resonance imaging) to detect a herniated disc;
• a PET scan or MRI if a cancerous tumor is suspected.

6. Treatment of Dysesthesia

There are a variety of potential treatments, depending on the primary cause of the dysesthesia. And doctors are sometimes forced to go through a process of elimination to find the right one for their patient if the dysesthesia is said to be "idiopathic" (i.e., without a known cause). Over-the-counter pain relievers, such as ibuprofen, are generally not effective in treating dysesthesia, according to the National Multiple Sclerosis Society. Dysesthesia is usually treated with the following medications:

• anticonvulsants (also called "antiepileptics"), which help alter the activity of the nervous system;
• certain antidepressants, which help modify the body's response to pain
• topical analgesic creams that contain lidocaine or capsaicin to relieve pain locally;
• opioids are rarely prescribed because of the high risk of dependence and are usually reserved for people with severe pain;
• antihistamines are sometimes prescribed for people with multiple sclerosis to relieve itching and burning;
• topical treatment, if the dysesthesia causes the patient to scratch the skin to the point of skin breakdown.

The doctor will start with the lowest possible dose and increase it if necessary. To avoid dangerous drug interactions, be sure to tell the doctor about all the medications you are taking, including herbal supplements. You can also alleviate the chronic pain associated with dysesthesia through natural treatments, combined with medications prescribed by your doctor:

• applying a warm or cold compress to the painful area;
• Wear socks or compression stockings;
• do gentle stretching exercises;
• Use a lotion containing aloe vera;

Take herbal capsules, such as Acorus calamus (sweet flag), Crocus sativus (saffron), and Ginkgo biloba.

When using herbs, consult your health care professional first to ensure that their active ingredients are compatible with the allopathic treatments you are taking.

7. How to prevent dysesthesia?

There are no real preventive measures for dysesthesia because it is more of a symptom than a disease. Prevention against this feeling of pain, therefore, involves prevention against pathologies or traumas that may be at the origin of it.

Sources:

Academy of Medicine, Multiple Sclerosis Information Site, College of Neurology Teachers, American Medical Association, National Library of Medicine, American Multiple Sclerosis Association