US expert consensus guidelines target advancing care in neuropathic pruritus
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Key takeaways:
- The authors identified definitions for neuropathic pruritus, including different forms of the condition.
- Diagnostic and treatment guidelines were also outlined.
Researchers have published an expert consensus on uniform nomenclature and diagnosis for neuropathic pruritus in the United States.
Published in Itch, the peer-reviewed journal of the International Forum for the Study of Itch, the consensus, authored by 10 experts and led by Shawn G. Kwatra, MD, director of the Johns Hopkins Itch Center and associate professor of dermatology at Johns Hopkins Medicine, was crafted to “offset these limitations in advancing the care of patients with neuropathic pruritus ... and offer guidance on diagnosis and workup.”
According to the study, the aforementioned limitations include an overall lack of data and limited diagnostic guidelines. The condition also has no distinct International Classification of Diseases, 10th Revision Code, causing it to be grouped with other forms of pruritus.
To create this consensus, the experts conducted a systematic review of prior literature on the definition, scope and diagnostics of neuropathic pruritus, as well as its treatment, from 1991 to 2021.
Definition
First, the authors defined neuropathic pruritus as “an itch primarily caused by a lesion of or disease affecting the somatosensory nervous system.” The core findings of this condition include the presence of normal skin or skin with only secondary changes or signs of excoriation, distinguishing it from primary inflammatory dermatoses.
Patients may have neuropathic pruritus if they present pain, stinging, burning or tingling that is paroxysmal or persistent in nature and does not respond to therapy. An additional tell of the condition is if a patient lacks features of systemic T helper type 2 polarization.
The itch primarily favors localization but can be generalized due to the fact that limited nerve damage can lead to heightened neurotransmitter release and hyperexcitable spinal neurons. The authors listed several subtypes of the disease with underlying causes including brachioradial pruritus, notalgia paresthetica, scalp pruritus and more.
Diagnostic workup
Diagnostic workup of the condition is not currently standardized, according to the study, but may be performed based on patient history.
For diffused cases, physicians must consider systemic causes for their patients’ pruritus and thus screen for organ function. Screening for cancer, infectious diseases, malignancies and blood count may also help in diagnosing the disease.
In localized cases, a radiologic examination of the area may be appropriate to identify spinal degeneration. For brachioradial pruritus, consider placing an ice pack on the skin to see if it relieves itchiness.
Physicians can also perform a neurological examination or skin biopsy to rule out other conditions.
Treatments
While treatment for this condition is anecdotal and based on limited reports, the authors compiled a list of topical, systemic and procedural therapies that may help.
Topical agents may include anesthetics, capsaicin cream or patch, coolants, tricyclic antidepressants, multiclass compounded medications or an ice pack.
For systemic agents, physicians may consider gabapentinoids, antidepressants, kappa/mu opioid axis modulators or cannabinoids.
Lastly, procedural therapies such as physical therapy, intralesional botulinum neurotoxin, CT-guided nerve root injections, transcutaneous electrical nerve stimulation, acupuncture or exploratory procedures including dorsal root ganglion stimulation may be used.
“Further development of studies examining the pathophysiology of neuropathic pruritus is greatly needed, as well as clinical trials for treatment approaches to the condition,” the authors concluded. “In addition, these findings may assist in the streamlining of International Classification of Diseases coding, using the diagnostic criteria mentioned within this paper.”