Notalgia paresthetica
Encyclopedia
Notalgia paresthetica is a chronic sensory
neuropathy. Notalgia paresthetica is a common localized itch, affecting mainly the interscapular area (especially the T2-T6 dermatomes) but occasionally with a more widespread distribution, involving the shoulders, back, and upper chest. The characteristic symptom
is pruritus (itch
or sensation that makes a person want to scratch) on the back
, usually on the left hand side below the shoulder blade (mid to upper back). It is occasionally accompanied by pain
, paresthesia
(pins and needles), and/or hyperesthesia
(unusual or pathologically increased sensitivity of the skin to sensory stimuli, such as pain, heat, cold, or touch), which results in a well circumscribed hyperpigmentation
of a skin patch in the affected area.
The causes or origin of this condition (etiology
) have not yet been completely defined.
Patients are usually older persons, and commonly find themselves scratching their back on doorposts etc, as the location can be hard to reach.
impingement may be a contributing cause. According to Plete and Massey, "The posterior rami of spinal nerves arising in T2 through T6 are unique in that they pursue a right-angle course through the multifidus spinae muscle, and this particular circumstance may predispose them to harm from otherwise innocuous insults of a varied nature." Patients may have other conditions that predispose them to peripheral neuropathies (nerve damage).
s, topical corticosteroid
s, and topical capsaicin
. Some patients treated with capsaicin reported pain, burning, or tingling sensations with treatment, and symptoms returned within a month of ceasing treatment. Oxcarbazepine
was reported to have reduced severity of symptoms in a few cases, but this was a reduction of symptoms rather than a cure. One patient has been treated with "paravertebral nerve blocks, with bupivacaine
and methylprednisolone
acetate injected into the T3-T4 and T5-T6 intervertebral spaces" Hydroxyzine
has also been used with some success.
Most recently intradermal injections of botulinum toxin
type A (Botox) have been tried with some success. Even though botulinum normally wears off in three to six months, the treatment appears to be long term, and it has been theorised that botulinum type A effects lasting change in pain signaling.
Somatosensory system
The somatosensory system is a diverse sensory system composed of the receptors and processing centres to produce the sensory modalities such as touch, temperature, proprioception , and nociception . The sensory receptors cover the skin and epithelia, skeletal muscles, bones and joints, internal...
neuropathy. Notalgia paresthetica is a common localized itch, affecting mainly the interscapular area (especially the T2-T6 dermatomes) but occasionally with a more widespread distribution, involving the shoulders, back, and upper chest. The characteristic symptom
Symptom
A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...
is pruritus (itch
Itch
Itch is a sensation that causes the desire or reflex to scratch. Itch has resisted many attempts to classify it as any one type of sensory experience. Modern science has shown that itch has many similarities to pain, and while both are unpleasant sensory experiences, their behavioral response...
or sensation that makes a person want to scratch) on the back
Human back
The human back is the large posterior area of the human body, rising from the top of the buttocks to the back of the neck and the shoulders. It is the surface opposite to the chest, its height being defined by the vertebral column and its breadth being supported by the ribcage and shoulders...
, usually on the left hand side below the shoulder blade (mid to upper back). It is occasionally accompanied by pain
Pain
Pain is an unpleasant sensation often caused by intense or damaging stimuli such as stubbing a toe, burning a finger, putting iodine on a cut, and bumping the "funny bone."...
, paresthesia
Paresthesia
Paresthesia , spelled "paraesthesia" in British English, is a sensation of tingling, burning, pricking, or numbness of a person's skin with no apparent long-term physical effect. It is more generally known as the feeling of "pins and needles" or of a limb "falling asleep"...
(pins and needles), and/or hyperesthesia
Hyperesthesia
Hyperesthesia is a condition that involves an abnormal increase in sensitivity to stimuli of the sense. "When a non-noxious stimulus causes the sensation of pain the area will be termed hyperaesthetic". Stimuli of the senses can include sound that one hears, foods that one tastes, textures that...
(unusual or pathologically increased sensitivity of the skin to sensory stimuli, such as pain, heat, cold, or touch), which results in a well circumscribed hyperpigmentation
Hyperpigmentation
In dermatology, hyperpigmentation is the darkening of an area of skin or nails caused by increased melanin.-Causes:Hyperpigmentation may be caused by sun damage, inflammation, or other skin injuries, including those related to acne vulgaris...
of a skin patch in the affected area.
The causes or origin of this condition (etiology
Etiology
Etiology is the study of causation, or origination. The word is derived from the Greek , aitiologia, "giving a reason for" ....
) have not yet been completely defined.
Patients are usually older persons, and commonly find themselves scratching their back on doorposts etc, as the location can be hard to reach.
Causes
The correlation of notalgia paresthetica localization with corresponding degenerative changes in the spine suggest that spinal nerveSpinal nerve
The term spinal nerve generally refers to a mixed spinal nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body...
impingement may be a contributing cause. According to Plete and Massey, "The posterior rami of spinal nerves arising in T2 through T6 are unique in that they pursue a right-angle course through the multifidus spinae muscle, and this particular circumstance may predispose them to harm from otherwise innocuous insults of a varied nature." Patients may have other conditions that predispose them to peripheral neuropathies (nerve damage).
Treatment
Many treatments have been tried, including local anestheticLocal anesthetic
A local anesthetic is a drug that causes reversible local anesthesia, generally for the aim of having local analgesic effect, that is, inducing absence of pain sensation, although other local senses are often affected as well...
s, topical corticosteroid
Corticosteroid
Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex. Corticosteroids are involved in a wide range of physiologic systems such as stress response, immune response and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte...
s, and topical capsaicin
Capsaicin
Capsaicin 2CHCH=CH4CONHCH2C6H3-4--3- ) is the active component of chili peppers, which are plants belonging to the genus Capsicum. It is an irritant for mammals, including humans, and produces a sensation of burning in any tissue with which it comes into contact...
. Some patients treated with capsaicin reported pain, burning, or tingling sensations with treatment, and symptoms returned within a month of ceasing treatment. Oxcarbazepine
Oxcarbazepine
Oxcarbazepine is a anticholinergic anticonvulsant and mood stabilizing drug, used primarily in the treatment of epilepsy. It is also used to treat anxiety and mood disorders, and benign motor tics...
was reported to have reduced severity of symptoms in a few cases, but this was a reduction of symptoms rather than a cure. One patient has been treated with "paravertebral nerve blocks, with bupivacaine
Bupivacaine
Bupivacaine is a local anaesthetic drug belonging to the amino amide group. AstraZeneca commonly markets it under various trade names, including Marcain, Marcaine, Sensorcaine and Vivacaine.-Indications:...
and methylprednisolone
Methylprednisolone
Methylprednisolone is a synthetic glucocorticoid or corticosteroid drug. It is marketed in the USA and Canada under the brand names Medrol and Solu-Medrol. It is also available as a generic drug....
acetate injected into the T3-T4 and T5-T6 intervertebral spaces" Hydroxyzine
Hydroxyzine
Hydroxyzine is a first-generation antihistamine of the diphenylmethane and piperazine classes. It was first synthesized by Union Chimique Belge in 1956 and was marketed by Pfizer in the United States later the same year, and is still in widespread use today....
has also been used with some success.
Most recently intradermal injections of botulinum toxin
Botulinum toxin
Botulinum toxin is a protein produced by the bacterium Clostridium botulinum, and is considered the most powerful neurotoxin ever discovered. Botulinum toxin causes Botulism poisoning, a serious and life-threatening illness in humans and animals...
type A (Botox) have been tried with some success. Even though botulinum normally wears off in three to six months, the treatment appears to be long term, and it has been theorised that botulinum type A effects lasting change in pain signaling.