Notalgia paresthetica: a review for dermatologists

Notalgia Paresthetica Review: Update on Presentation, Pathophysiology, and Treatment

PURPOSE OF REVIEW

Notalgia paresthetica (NP) is a chronic cutaneous neuropathy primarily characterized by localized pruritus and associated dysesthesias, including sensations of pain, numbness, and tingling. The sensory neuropathy characteristic of NP is thought to result from spinal nerve entrapment caused by degenerative changes in the spine or musculoskeletal compression. This review summarizes the current medical literature with a focus on the past five years regarding NP, its pathophysiology, presentation, and current treatment options.

RECENT FINDINGS

Though treatments exist with varying efficacy, to date, there exists no definitive treatment for NP. Treatment options for NP are varied and range from topical and oral agents to interventional procedures and physical therapy. Of the treatments evaluated, topical capsaicin remains the most efficacious treatment for NP.

CONCLUSIONS

The lack of established treatment guidelines makes treating NP complicated as it dramatically affects patients' quality of life. Further research with larger sample sizes is needed to evaluate better the most effective treatment and dosing regimen for patients afflicted with NP.

Phase 2 Trial of Difelikefalin in Notalgia Paresthetica

BACKGROUND

Notalgia paresthetica is a neuropathic disorder characterized by pruritus in a circumscribed region of the upper back. Difelikefalin, a selective kappa opioid receptor agonist, has shown efficacy in other chronic pruritic conditions and is being investigated for the treatment of notalgia paresthetica.

METHODS

In this phase 2, double-blind, placebo-controlled trial, we randomly assigned, in a 1:1 ratio, patients with moderate-to-severe pruritus caused by notalgia paresthetica to receive 2 mg of oral difelikefalin or placebo twice daily for 8 weeks. The primary outcome was the change from baseline at week 8 in the weekly mean score on the daily Worst Itch Numeric Rating Scale (WI-NRS; scores range from 0 [no itch] to 10 [worst itch imaginable]). The secondary clinical outcomes were itch-related quality-of-life and itch-related sleep measures.

RESULTS

A total of 126 patients were enrolled; 62 patients were assigned to receive difelikefalin, and 63 were assigned to receive placebo. One patient who had been assigned to receive difelikefalin withdrew consent before the first dose and is not included in the main analyses. The mean baseline WI-NRS score was 7.6 (indicating severe itch) in each group. The change from baseline in the weekly mean WI-NRS score at week 8 was -4.0 points in the difelikefalin group and -2.4 points in the placebo group (difference in change, -1.6 points; 95% confidence interval, -2.6 to -0.6; P = 0.001). The results for the secondary outcomes generally did not support those of the primary analysis. Headache, dizziness, constipation, and increased urine output occurred more frequently in the difelikefalin group than in the placebo group.

CONCLUSIONS

Among patients with notalgia paresthetica, oral treatment with difelikefalin resulted in modestly greater reductions in itch intensity scores than placebo over a period of 8 weeks but was associated with adverse events. Larger and longer trials are needed to assess the efficacy and safety of difelikefalin treatment in this disorder. (Funded by Cara Therapeutics; KOMFORT ClinicalTrials.gov number, NCT04706975.).

Successful treatment of notalgia paresthetica with lidocaine 5% medicated plaster: a case report

Notalgia paresthetica (NP) is a sensory neuropathy characterized by chronic, localized pruritus in a circumscribed area on the upper back. Pruritus, frequently resistant to treatment, may be accompanied by pain, paresthesia, allodynia and alloknesis. There is a paucity of data in the NP literature about the use of lidocaine 5% medicated plaster. This case involves a 75-year-old woman with NP and a history of many unsuccessful local or systemic treatments. The patient was treated with lidocaine 5% medicated plaster, while other therapies were progressively retired. After 11 weeks of therapy, a significant reduction in the intensity of itching was achieved and the itching area was reduced. The patient also reported an associated improvement in her quality of life throughout therapy. In conclusion, lidocaine 5% medicated plaster was successful in relieving itching and other symptoms in this case of NP.

Understanding the patient experience of living with notalgia paresthetica: A qualitative interview study

Background

Notalgia paresthetica (NP) is a chronic sensory neuropathy that causes intense pruritus, typically affecting the upper portion of the back and lasting for months to years. The impacts of pruritus and the full symptom experience are not well documented.

Objective

To describe patients’ NP symptom experience and the impacts of living with NP-related itch.

Methods

Semistructured, one-to-one qualitative telephone interviews were conducted in adults living with NP. The worst itch severity during the previous 24 hours was assessed using an 11-point numerical rating scale.

Results

Thirty participants (23 females; aged 41-80 years) completed interviews. Seventeen NP-related symptoms were described, with daily itch being the most common. Participants’ itch ranged from severe to very severe (50%) and was experienced for a median of 2.8 years. Most (73%) participants were not receiving treatment for NP at the time of the study. Other reported symptoms included skin pain or sensitivity and secondary symptoms from itching (skin discoloration, lumps or bumps, bleeding or scabbing). NP-related itch was frequently reported to affect mood, interfere with sleep, and disrupt self-care.

Limitations

Only English-speaking participants living in the United States were included.

Conclusion

This study highlights the patient experience of living with NP and findings reveal that there remains an unmet need for effective therapeutic options to address NP-related itch.

Notalgia paresthetica: An underdiagnosed condition in primary care

ABSTRACT

Notalgia paresthetica is a perplexing diagnosis in the primary care setting. Chronic itching, paresthesia, or pain causes discomfort in patients who suffer with notalgia paresthetica and it is thought to be a common but underdiagnosed condition. Recognition of this dermatologic condition can lead to reassurance and relief for affected patients.

Notalgia Paresthetica: Cervical Spine Disease and Neuropathic Pruritus

Notalgia paresthetica (NP) is a dermatologic condition with predominant, primarily left unilateral pruritus and hyperpigmentation that typically occurs on the upper and middle back. The etiology remains largely elusive. A 57-year-old female with a history of neck pain presented with refractory NP since six months. Through diagnostic x-ray, cervical degenerative changes were discovered at the C5-C6 level, and she was prescribed a course of cervical traction. The cervical theory of NP is presented and is supported with x-ray findings in this case.

Notalgia paresthetica: clinical features, radiological evaluation, and a novel therapeutic option

Background/objective

Notalgia paresthetica (NP) is a sensory neuropathy characterized by localized pruritus and pain, presenting with or without a well-circumscribed hyperpigmented patch in the upper back. Abnormal sensations, such as burning, numbness, and paresthesia are often present in patients with NP. In this study, we clinically and radiologically analyzed patients with NP. The literature contains studies describing lidocaine treatments involving intravenous and topical applications for NP. We also investigated the effect of intradermal lidocaine injection on patients with NP.

Methods

A total of 80 patients (45 patients with NP and 35 suffering from dorsalgia without NP) were included in the study. The age, gender and body mass index (BMI) of the patients, and the characteristics of their symptoms were recorded. The severity of pain and pruritus was assessed by the Visual Analog Scale (VAS). Radiography and magnetic resonance imaging of the spine were performed. In this study, we intradermally administered lidocaine diluted with saline into the upper back over three sessions. 1 cc 2% lidocaine was diluted with 5 cc 0.9% saline, and a total of 6 cc lidocaine mixture was obtained. The injection was performed locally at 1-cm intervals around the hyperpigmented patch and segmentally along the C2-T6 spinous processes. These patients were called for a follow-up at the second and fourth weeks and third month.

Results

There was no statistically significant difference between the two groups in terms of age, BMI, VAS-pain score, and duration of symptoms (p > 0.05 for all). Forty-six cervical and/or thoracic degenerative changes or herniated nucleus pulposus (HNP) were detected in patients with NP. There was a significantly higher number of HNP at the C6–7 segment and cervical degenerative changes in the NP group (p < 0.05). The VAS-pain and VAS-pruritus scores were significantly decreased at all follow-up sessions, and improvement was sustained by lidocaine up to the third month.

Conclusion

Cervical degenerative changes and HNP of the C6–7 segment seem to be contributing factors for NP. Local lidocaine can be effective for pain relief and pruritus in NP.