Comparison of Characteristics of Neuropathic and Non-neuropathic Pruritus to Develop a Tool for the Diagnosis of Neuropathic Pruritus: The NP5

[Neuropathy in pruritus medicine : Recommended diagnostics and therapy]

Chronic itch is a frequent and debilitating condition that greatly affects the quality of life of those affected. In a subset of patients, damage to the peripheral or central nervous system constitutes the cause of the itch. Small-fiber neuropathy, nerve compression syndromes, post-herpetic neuralgia, scars and burns are possible conditions affecting the peripheral nervous system potentially causing itch, whereas space-occupying lesions affecting the spinal cord and stroke are examples of conditions that may induce central itch. Neuropathic itch starts on normal appearing skin, is often accompanied by pain sensations and other dysesthesias, and usually relieved by local cold application. Its distribution depends on the affected site of the somatosensory system. A comprehensive medical history is paramount to reach the diagnosis, while complementary diagnostics with skin biopsies for the investigation of cutaneous neuromorphological alterations or medical imaging to rule out nerve impingement may be advised in selected cases. Topical agents such as capsaicin or local anesthetics as well as systemic drugs such as gabapentinoids, antidepressants and opioid receptor modulators are used in the treatment of neuropathic itch. This review article provides an overview of the clinical features, underlying causes, diagnostic workup and therapeutic approach in neuropathic itch.

Aetiology, pathogenesis and management of neuropathic itch: A narrative review with recent updates

Neuropathic itch is a relatively common yet under-reported cause of systemic pruritus. It is a debilitating condition often associated with pain, which impairs the patient's quality of life. Although much literature exists about renal and hepatic pruritus, there is a dearth of information and awareness about neuropathic itch. The pathogenesis of neuropathic itch is complex and can result from an insult at any point along the itch pathway, ranging from the peripheral receptors and nerves until the brain. There are several causes of neuropathic itch, many of which do not produce any skin lesions and are thus, often missed. A detailed history and clinical examination are necessary for the diagnosis, while laboratory and radiologic investigations may be needed in select cases. Several therapeutic strategies currently exist involving both non-pharmacological and pharmacological measures, the latter including topical, systemic, and invasive options. Further research is ongoing to clarify its pathogenesis and to design newer targeted therapies with minimal adverse effects. This narrative review highlights the current understanding of this condition, focusing on its causes, pathogenesis, diagnosis, and management, along with newer investigational drugs.

Psychogenic and neurogenic components in patients with psychogenic or neuropathic pruritus: PRURINEURO: A non-interventional single-centre prospective assay

Background

The causes of pruritus are multiple and commonly classified into six different categories: dermatological, systemic, neuropathic, psychogenic, mixed and idiopathic. In clinical practice, psychogenic and neurogenic mechanisms tend to be separated in the etiological diagnosis of neuropathic or psychogenic disorders; nevertheless, studies investigating the respective psychogenic and neurogenic components are lacking.

Objective

The main objective of this work was to highlight the differences and potential common characteristics between psychogenic pruritus and neuropathic pruritus.

Methods

This study was a noninterventional single-centre prospective assay. Patients with neuropathic (NP) or psychogenic (PP) pruritus were proposed to participate. The psychogenic and neurogenic components of pruritus in these patients were evaluated using six validated questionnaires or criteria, namely, the diagnosis criteria of psychogenic pruritus, the NP5 questionnaire, the Brest Pruritus Qualitative Assessment Questionnaire, Hospital Anxiety and Depression Scale, Toronto Alexithymia Scale, and DN4i.

Results

Twenty-five patients with NP and 15 with PP were included. A difference between the two groups was observed for NP5, with mean scores of 2.8 ± 0.9 and 1.4 ± 1 for the NP and PP groups, respectively (p < 0.0001). For depression, the average score was 3.5 ± 3.9 for the NP group and 7.5 ± 5.1 for the PP group (p < 0.02).

Conclusion

While neuropathic and psychogenic disorders are different diagnoses, neuropathic and psychogenic components may exist simultaneously in patients with NP or PP.

Treatment Algorithm for Cancerous Wounds: A Systematic Review

BACKGROUND

In advanced cancer stage the incidence of cancerous wounds is about 5%, and the estimated life expectancy is not more than 6 to 12 months. Without interdisciplinary and individualized treatment strategy, symptoms progress, and adversely influence quality of life.

METHODS

Authors collected different treatment algorithms for cancerous wound published by wide scale of medical expertise, and summarized surgical, oncological, radiation oncological, nursing and palliative care aspects based on radiological information.

RESULTS

Interdisciplinary approach with continuous consultation between various specialists can solve or ease the hopeless cases.

CONCLUSIONS

This distressing condition needs a comprehensive treatment solution to alleviate severe symptoms. Non-healing fungating wounds without effective therapy are severe socio-economic burden for all participants, including patients, caregivers, and health services. In this paper authors collected recommendations for further guideline that is essential in the near future.

Pruritus, Pain, and Depression Associated with the Most Common Skin Diseases: Data from the French Study "Objectifs Peau"

BACKGROUND

The prevalence and impact of pruritus, pain, and other sensory symptoms in skin diseases are poorly known.

OBJECTIVE

To assess the frequency of these symptoms with dermatoses and their association with depression using data from the "Objectifs Peau" survey.

METHODS

A representative sample of 20,012 French individuals was created using the usual quota method.

RESULTS

When patients suffered from both pruritus and skin pain, they had a higher relative risk of psychological suffering (2.9) than those who suffered only from pruritus (1.4) or skin pain (1.2). Pruritus was reported in 48.55% of patients with acne, 43.24% with mycoses, 44.35% with warts, and 36.51% with rosacea. For skin pain, the results were 11.22%, 27.59%, and 16.13% for atopic dermatitis, acne, and warts, respectively. Other unpleasant sensations, such as tingling or burning, were also frequently reported.

CONCLUSION

Pruritus, pain, or other sensory symptoms were found to be common not only in classic pruritic skin diseases but also in acne, rosacea, or warts. The association of pruritus and pain dramatically increased psychological suffering. These symptoms must be systematically searched for in patients, especially since new therapeutic possibilities are emerging for the symptomatic treatment of pruritus.

Neuropathic Itch: Routes to Clinical Diagnosis

Neuropathic itch occurs due to damage of neurons of the peripheral or central nervous system. Several entities, including metabolic, neurodegenerative, orthopedic, infectious, autoimmune, malignant, and iatrogenic conditions, may affect the somatosensory system and induce neuropathic itch. Due to the complex nature of neuropathic itch, particularly concerning its clinical presentation and possible etiological factors, diagnostic work-up of this condition is challenging. A detailed medical history, especially in regard to the itch, and a comprehensive physical examination are relevant to detect characteristic signs and symptoms of neuropathic itch and to rule out other possible causes for chronic itch. Complementary diagnostic exams, especially laboratory tests, determination of the intraepidermal nerve fiber density via a skin biopsy and radiological examinations may be indicated to confirm the diagnosis of neuropathic itch and to identify underlying etiological factors. Functional assessments such as quantitative sensory testing, nerve conduction studies, evoked potentials, or microneurography may be considered in particular cases. This review article provides a comprehensive overview of the diagnostic work-up recommended for patients with neuropathic itch.