Chronic pruritus in multiple sclerosis and clinical correlates

Abstract

Background:To date, little is known about the prevalence of itch in multiple sclerosis (MS) and its characteristics.Objectives: In this cross-sectional study, we assessed the prevalence, intensity and characteristics of chronic pruritus in MS patients and its effect on quality-of-life and association with MS symptoms, clinical signs, comorbidities and MRI findings.Methods: MS patients presenting to an outpatient neurology clinic were asked about their current symptoms. Those who experienced chronic pruritus were administered the Standardized Itch Questionnaire and Itch Quality of Life forms. All patients' medical records were reviewed. Patients with any medical conditions associated with chronic itch were excluded.Results: Seventy-seven total MS patients were included, and 27 (35%) reported pruritus. The average itch NRS severity was 5.42 (range 0-10). The most affected body parts were the extremities, face or scalp, and trunk. Itch was characterized as acute (74%), paroxysmal (59%) and tingling (55%). Heat (52%) was the most common aggravating factor, while cold temperatures had no effect.Compared with MS patients without itch, itch patients reported more fatigue (77% vs 44%, p = 0.004), heat sensitivity (48% vs 20%, p = 0.0177), cognitive impairment (62% vs 26%, p = 0.0029) and depression or anxiety (48% vs 16%, p = 0.0063).Additionally, itch patients had more T2 hyperintensities in the posterior cervical cord and anterior pons/ventromedial medulla (74.1% vs 46.0%, p = 0.018 and 29.6% vs 8.0%, p = 0.020, respectively). Finally, T2 hyperintensities in the anterior pons/ ventromedial medulla were strongly associated with itch localized to the face or scalp (OR 11.3,, p = 0.025). Conclusion:MS patients experience paroxysmal neuropathic pruritus that is most frequently localized to the extremities, face or scalp. Patients with itch were more likely to have MS-related comorbidities and demyelinating lesions in the spinal cord or brainstem.

Neuropathic Pruritus: An Underrecognized and Often Misdiagnosed and Difficult to Treat Medical Condition

“…Paroxysmal pruritus associated with neuroinflammatory conditions (demyelinating diseases) such as multiple sclerosis and neuromyelitis optica is clinically an acute onset and recalcitrant pruritus that is usually triggered by the onset of movement and has frequent attacks during the day. It has been theorized that transversely diffused ephatic activation of partially demyelinating pain-transmitting neurons causes paroxysmal pruritus [51][52][53]. In the study of Ingrasci et al, pruritus was reported in 35% of a total of 77 multiple sclerosis patients.…”

“…As a result, paroxysmal NP localized to the extremities, face or scalp, most frequently, is seen in multiple sclerosis patients. Patients with pruritus are more likely to have multiple sclerosis-related comorbidities and demyelinating lesions in the spinal cord or brainstem [51]. Muto et al have suggested that most of the opticospinal form of multiple sclerosis is neuromyelitis optica, and it was found that paroxysmal pruritus was more prominent in these cases [52].…”

“…MRI and CT play an important role in detecting space-occupying lesions (such as tumors, abscesses, and vascular or inflammatory lesions) and their anatomical relationship with peripheral or central neural structures [30,36,60], as well as in the diagnosis of neurological conditions such as stroke, meningitis, or degenerative neuroinflammatory diseases that can cause NP [49][50][51][52][53]. In the diagnostic study of itchy neuropathic compression syndromes, MRI, CT, high-resolution sonography, or MR neurography are also used to identify underlying pathologies such as compression of the nerve roots or spinal cord, disc prolapse or herniation, degenerative vertebral changes, osteophytes, or neuroforaminal stenosis [25,27].…”

United States expert panel consensus on uniform nomenclature and diagnosis for neuropathic pruritus

“…Central nerve and peripheral nerve damage secondary to illness, syndromes, or surgery can also elucidate pruritus [21] . Common examples include poststroke, postherpetic, or postsurgical pruritus and multiple sclerosis [22][23][24][25] .…”