MS Signs & Symptoms: What is Pruritus?
I’ve got a recurring itch that sometimes drives me batty. It shows up right in the middle of my back and is often just out of reach. It’s a crazy itch that is difficult to satisfy.
“Rob, can you scratch my back, please?”
One time when I was checking my medical records, I noticed an unfamiliar diagnosis - Notalgia Paresthetica. I wanted to know what that meant; so like any good MS advocate and health writer, I looked it up.
What is notalgia paresthetica?
Notalgia paresthetica (NP) is a common sensory neuropathic syndrome of the mid-back skin, characterized by localized pruritus (itching) beneath the shoulder blades. NP may also affect the upper back, scalp, and shoulders. Chronic pruritus is sometimes accompanied by pain, paresthesias, or altered sensation to touch.
This particular type of neuropathy is thought to be caused by a problem with the neck, such as degenerative disc disease (i.e., osteoarthritis), bulging disc, pinched nerve, or muscle spasm. Notalgia is more common in adulthood (in persons aged 40-80) and tends to occur more in individuals who have a lower threshold to itch, including those with multiple sclerosis or other autoimmune conditions.
Pruritus and multiple sclerosis
Did you know that intense itching can be a symptom of multiple sclerosis? It’s not the most common symptom associated with MS, but one which can be rather annoying, comes on suddenly, and is sometimes downright painful.
Pruritus, or itching, is defined as an unpleasant sensation of the skin that provokes the urge to scratch. The itch can be localized or widespread, acute or chronic, and range from mild to intractable (hard to control). Itching can occur anywhere on the body.
Pruritus is associated with many skin disorders (e.g. eczema, psoriasis), histamine reactions (e.g. insect bites, poison ivy), and some systemic diseases (e.g. Sjögren's syndrome, hyperthyroidism, liver disease, diabetes). Pruritus can also be associated with neurologic or psychiatric disease, certain blood disorders (e.g. leukemia, iron deficiency, multiple myeloma), and reaction to medications (e.g. opioids, estrogen, simvastatin).
Itchiness as an MS symptom
When pruritus occurs as a symptom of multiple sclerosis, it is similar to other neurologic sensations - pins and needles, burning, stabbing, or tearing pain - known as dysesthesias. The itching with MS is often paroxysmal (coming on suddenly with great intensity) but temporary in nature and lasting anywhere from a couple of seconds to minutes. It can even seem to get worse the more you scratch.
Heat triggers pruritus for some people with MS and for others, it seems to be related to movement or tactile stimulation. For some reason, the itching often occurs at night with an intensity that has the power to wake you up from sleep.
Other causes of MS-related itching may include temporary skin irritation following injections, allergic reaction to medication, or side-effect of medication. In clinical trials, one of the common side effects of the oral medication dimethyl fumarate (Tecfidera) was flushing, followed by the sensation of heat or itching.
Alai AN. Notalgia Paresthetica (updated 11 May 2015). In: Medscape Drugs and Diseases. Retrieved 12 July 2015 from http://emedicine.medscape.com/article/1599159-overview
Ellis C. Notalgia paresthetica: the unreachable itch. Dermatol Pract Concept. 2013 Jan; 3(1): 3–6. Published online 31 Jan 2013. doi: 10.5826/dpc.0301a02
Taylor JS, Zirwas, MJ, Sood A. Pruritus. In: Disease Management Project (Dermatology). Cleveland Clinic Center for Continuing Education. Retrieved 12 July 2015 from http://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/dermatology/pruritus-itch/