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.
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.
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MS Signs vs Symptoms: What is Pruritus?
(Photo credit: "Scratching her head" by Tambako is licensed under CC BY-ND 2.0)
See also: Treatment for MS-Related Itching