Holistic approach to treatment of intractable central 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.

Effects of Stress on Itch

PURPOSE

Psychological stress and ensuing modulation of the immune and nervous systems can have a significant impact on itch. Stress can exacerbate itch and vice versa, resulting in a vicious cycle that can greatly impair a patient's quality of life. This review summarizes the association between stress and itch, elucidates the mechanism by which these two phenomena influence one another, and explores treatment modalities that aim to reduce stress-induced itch.

METHODS

A complete search of the PubMed and Google Scholar databases was completed and literature pertinent to this review was compiled.

FINDINGS

Both acute and chronic stress can significantly affect itch in healthy individuals and in those diagnosed with itchy skin diseases as well as systemic diseases, thus resulting in a vicious cycle in which stress exacerbates itch and vice versa. The mechanisms by which stress induces or aggravates itch include both central and peripheral activation of the hypothalamic-pituitary-adrenal axis and sympathetic nervous system. Activation of these systems, in turn, affects the mast cells, keratinocytes, and nerves that secrete neuropeptides, such as substance P, nerve growth factor, acetylcholine, histamine, and itchy cytokines. A dysfunctional parasympathetic response is thought to be involved in the chronic stress/itch response. Brain structures associated with emotion, such as the limbic system and periaqueductal gray, which work on the descending facilitation of itch, play a significant role in stress-induced itch.

IMPLICATIONS

As specific brain structures are associated with stress, drug treatments targeting these areas (ie, γ-aminobutyric acid-ergic drugs, serotonin and norepinephrine reuptake inhibitors) may help to modulate itch. Stress can also be combatted using nonpharmacologic treatments such as cognitive-behavioral therapies and stress-relieving holistic approaches (eg, yoga, acupuncture).

Biofield Therapies for Symptom Management in Palliative and End-of-Life Care

Terminally ill patients experience negative symptoms at end of life (EOL) that hinder well-being and quality of life (QOL). Current intervention strategies are not always effective or feasible. A focused literature review to evaluate the use of biofield therapies (ie, Therapeutic Touch, Healing Touch, and Reiki) to manage the symptoms in EOL revealed no studies on the use these therapies, specifically in this population. Evidence from studies on relevant populations (patients with cancer, elderly patients, and patients experiencing chronic pain), which addressed the outcomes relevant to palliative and EOL care (EOLC; pain levels, changes in psychological symptoms, well-being, and QOL), supports the use of biofield therapies in relieving pain, improving QOL and well-being, and reducing psychological symptoms of stress. Further research to assess the use of biofield therapies in EOLC is clearly needed.

Trigeminal trophic syndrome from stroke: an under-recognized central neuropathic itch syndrome

Trigeminal trophic syndrome (TTS) is the historic name for neuropathic self-induced facial ulceration from abnormal sensory symptoms leading to uncontrolled scratching. Anatomic co-localization of sensory loss (numbness) plus neuropathic itch and pain permits painless scratching. If the itch is severe, some patients will scratch to the point of causing self-injury. Patients may be unaware or may conceal the fact that their lesions are self-induced and thus the diagnosis presents a clinical challenge. Many cases remain undiagnosed, leading to unnecessary and ineffective tests, procedures, and prescribing. We document a patient with a central cause of TTS - multiple cerebral vascular accidents - and summarize the presentation, pathogenesis, and treatment options.

Pruritus: management algorithms and experimental therapies

Pruritus (itch) is a major symptom in many dermatologic as well as systemic diseases and has a dramatic impact on the quality of life in these patients. The symptom of itch has to be treated on the basis of its pathophysiology and its underlying disease. In daily practice, a "quick" diagnosis of the underlying disease is often difficult, although a rapid relief of the itch is desired. We often treat patients on the basis of the symptomatology. A rational therapeutic ladder for a symptomatic therapy is useful until the final diagnosis has been confirmed. There are probably many subtypes of pruritus, just as there are many diseases that cause itch. The pathophysiology in many subtypes of pruritus is still poorly understood, hindering a rapid and targeted treatment strategy. An extensive diagnostic workup is often required to determine the final cause(s) of the itch. Thus, in daily life, physicians often start with a more or less rational therapeutic strategy to combat the debilitating itch. We present possible therapeutic ladders that form the basis for effective therapeutic itch strategies in various diseases. On the basis of our current knowledge about the different pathophysiologies of itch, on clinical trials or case reports, and our own clinical experience, we aim to present therapeutic ladders for the rapid as well as long-term management of itch. Finally, we summarize current exciting developments of experimental strategies in itch research and in clinical development for itch therapy.

Preservation of immune function in cervical cancer patients during chemoradiation using a novel integrative approach

Patients receiving chemoradiation for cervical cancer are at risk for distress, chemoradiation-related side-effects, and immunosuppression. This prospective randomized clinical trial examined effects of a complementary therapy, Healing Touch (HT), versus relaxation training (RT) and usual care (UC) for (1) supporting cellular immunity, (2) improving mood and quality of life (QOL), and (3) reducing treatment-associated toxicities and treatment delay in cervical cancer patients receiving chemoradiation. Sixty women with stages IB1 to IVA cervical cancer were randomly assigned to receive UC or 4 ×/weekly individual sessions of either HT or RT immediately following radiation during their 6-week chemoradiation treatment. Patients completed psychosocial assessments and blood sampling before chemoradiation at baseline, weeks 4 and 6. Multilevel regression analyses using orthogonal contrasts tested for differences between treatment conditions over time. HT patients had a minimal decrease in natural killer cell cytotoxicity (NKCC) over the course of treatment whereas NKCC of RT and UC patients declined sharply during chemoradiation (group by time interaction: p = 0.018). HT patients showed greater decreases in two different indicators of depressed mood (CES-D depressed mood subscale and POMS depression scale) compared to RT and UC (group by time interactions: p<0.05). No between group differences were observed in QOL, treatment delay, or clinically-rated toxicities. HT may benefit cervical cancer patients by moderating effects of chemoradiation on depressed mood and cellular immunity. Effects of HT on toxicities, treatment delay, QOL, and fatigue were not observed. Long-term clinical implications of findings are not known.