Neuropathic Itch More Common in Multiple Sclerosis Than Previously Thought

Paroxysmal neuropathic pruritus was found in many patients with multiple sclerosis (MS) and was more common among patients with spinal cord and brainstem lesions. These findings, from a cross-sectional study, were published in the Journal of the European Academy of Dermatology & Venerology.

Patients (N=77) with MS were recruited at the Multiple Sclerosis Center of Excellence in Miami, FL. Symptoms of itch were evaluated using the Standardized Itch Questionnaire which assesses itch using the 10-point numeric rating scale (NRS) or Likert scale and the Itch-Specific Quality of Life (ItchyQol). The prevalence and characteristics of chronic pruritus were evaluated.

More than a third of patients (35%) reported itch. The itch and no itch cohorts comprised 81.5% and 62% women, mean age of 46.5±14.3 and 40.1±14.6 years, 88.9% and 78% had relapsing remitting disease, and 14.8% and 24% were not using disease modifying medications, respectively.

Patients with itch more frequently had cognitive impairment (63% vs 26%; P =.002), anxiety or depression (48% vs 16%; P =.003), fatigue (77.8% vs 44%; P =.004), and heat sensitivity (48.1% vs 20%; P =.010) compared with the no itch cohort, respectively. In addition, the magnetic resonance imaging (MRI) data indicated itch was associated with a higher rate of posterior cervical spinal cord lesions (74% vs 46%; P =.03) and anterior pons or rostral medulla lesions (29.6% vs 8%; P =.02) compared with no itch, respectively.

Patients with itch reported an average itch intensity of 5.42±2.63, a frequency of 3.31±2.94 daily attacks, lasting 14.16±11.43 minutes, during a duration of 3.35±3.21 years, and a scratch pleasurability score (range, -5 to 5) of 1.6±2.59, respectively. According to the ItchyQol, itch had a mild effect on quality of life. More than half of patients (52%) said the itch “drove them crazy or nuts.”

On a day with itch, more patients had intermittent itching (77.7%) than constant itching (22.3%); itch attacks tended to occur in the evening (88.88%) compared with the morning (70.3%); and they occurred more often in the spring (66.66%) followed by the summer (62.96%), fall (51.8%), and winter (48.1%). Itch manifested as tingling (55%) or stinging (45%), occurring most frequently in the upper extremities (51.9%), followed by the lower extremities (48.1%), face or scalp (37%), and the trunk (29.6%). Heat (52%) and stress (45%) were common aggravating factors.

This study was limited by its small sample size and lack of longitudinal data. Investigators noted that it remains unclear whether itch symptoms change over time.

Study authors concluded, “Health care providers should be aware of episodes of localized, neuropathic itch in MS patients, as they appear to be more prevalent than previously thought and may impair these patients’ quality of life. MS patients who experience itch seem to have an increased risk of experiencing MS-related symptoms, as well as having spinal cord and brainstem lesions.”

Disclosure: Multiple authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.

Reference

Ingrasci G, Tornes L, Brown A, et al. Chronic pruritus in multiple sclerosis and clinical correlates. J Eur Acad Dermatol Venereol. Published online August 26, 2022. doi:10.1111/jdv.18561