Neuropathic Brachioradial Pruritus: Capsaicin and Other Topical Treatments to Stop Arm Itching
Who has perfectly healthy skin with constant incurable itching? When the unbearable itching is limited to the arms, the answer is a person with neuropathic brachioradial pruritus—a condition that’s more frustrating than the most difficult riddles.
By the time these patients come into your pharmacy, they’re exhausted from itch-induced insomnia and desperate for relief.
They don’t know it yet, but they need expert advice because the typical OTC itch-relief products won’t be effective. Pharmacists who find a way to reach out can help these patients understand the nature of their disease and can guide treatment choices.
Overview of Neuropathic Brachioradial Pruritus
Brachioradial pruritus was once thought to be isolated to tropical climates, but it’s also found in more temperate locations. In the United States, cases have been reported in such diverse regions as Massachusetts, Florida, Kansas and California.1 It has a simple definition—it’s a neurogenic itch syndrome of the arms, often localized to the forearm but sometimes involving the upper arms—yet treatment is anything but easy and straightforward.
The most common cause of brachioradial pruritus is nerve root compression.2 Magnetic resonance tomography showed cervical nerve compression in 80.5 percent of patients, reported a study in the Journal of the American Academy of Dermatology in October 2011.3 These patients didn’t have neck pain; their only symptom was itchy skin downstream from the compressed nerve.
The remaining patients in the study had degenerative changes in the spine that didn’t correlate to the dermatomal localization of their pruritus. While multimodal causes are likely at play in some patients, brachioradial pruritus is not well studied, so further research is needed to nail down answers.
Other relevant information from the October 2011 study, which included 41 patients diagnosed with brachioradial pruritus, included:
- Skin biopsies showed normal, healthy skin except for changes like leathering and scratch marks caused by chronic scratching.
- Itching started in the dermatome of the nerves at cervical vertebra 6, which corresponds to the outside surface of the forearms over the brachioradial muscle.
- Both arms were affected in about half of the participants.
What Pharmacists Need to Know For Patient Counseling
The itching caused by brachioradial pruritus has characteristics that are different from the itch associated with common skin conditions, which is one of the most frustrating factors for patients who try to self-treat. Even though symptoms go into remission within a few months for most patients, they’re not cured. They’ll have to cope with this condition for an average of five years—some will have it as long as 18 years. Here’s a rundown of what patients with brachioradial pruritus experience:
- Intense, 24/7 itch often accompanied by burning and stinging sensations.
- The itching gets worse at night.
- Scratching only makes the itch worse.
- Touching sometimes makes it worse.
- Warmth, heat, sunlight and wind worsen symptoms.
When patients face unremitting symptoms over an extended period of time, they’re at risk for developing anxiety and depression, so this aspect of the disease must be addressed. They need to know it’s normal for the itching to take a toll on their emotions and sense of well-being. While more research is needed to verify the role of psychiatric factors, experts believe that emotional health influences the prognosis. Be prepared with basic information about the signs of depression and encourage patients to seek professional support.
Treatment Options for Brachioradialis Pruritus
Basic skin care to keep skin well hydrated is important, especially for people between the ages of 40 and 60. Brachioradialis pruritus primarily affects people in those age ranges. All patients should be advised to protect their arms from sunlight because it usually exacerbates symptoms. The itching remits within a few months for most patients.
In the meantime, the best relief is obtained by applying ice packs to the affected area. Unfortunately, this treatment is limited because most people can’t keep a cold compress on their arms at work, so they need other topical options. Medications and therapies your patients can try include:
- Capsaicin – 8 percent topical capsaicin patch is well tolerated; duration of itch relief varies from a few days to several months
- Doxepin cream – especially effective at bedtime.
- Compounded mixture of amitriptyline hydrochloride 1.0 percent, ketamine hydrochloride 0.5 percent and Vanicream applied two to three times daily relieved all symptoms in a patient with a five-year history of brachioradial pruritus
Oral medications – Common medications used for most types of itch, such as antihistamines and corticosteroids, usually aren’t effective for neuropathic itch. None of the oral agents work predictably in all patients, but these have proven to be effective in some:
A recent review of 49 patients with brachioradial pruritus found that 80 percent had symptom relief with monotherapy using tricyclic antidepressants, doxepin or antipsychotics.4 However, most treatment recommendations come from isolated case studies.
Alternative therapies – Deep intramuscular stimulation acupuncture, transcutaneous electrical nerve stimulation and physical therapy may help some patients.
Topical Treatment Advice Improves Outcomes
While they’re waiting for symptoms to remit, patients with brachioradial pruritus must make it through the day and keep up with their responsibilities while enduring the discomfort and distraction of a relentless itch. Pharmacists can work with each individual to find the topical agent—or a compounded mixture of active pharmaceuticals—that provides the most effective relief. You’ll also need to help them find products to improve sleep, whether that’s a stronger topical agent or an OTC product like melatonin. Your expertise makes all the difference for these patients who are in it for the long haul.
Pharmaceutica North America provides high-quality bulk APIs, compounding kits and prescription drug products—including topical lidocaine—to help patients with brachioradial pruritus. Contact us today to talk about how we can support all your pharmaceutical needs.
- “Brachioradial Pruritus,” August 2016, http://emedicine.medscape.com/article/1355312-overview ↩
- “Neuropathic Itch,” June 2011, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3139924/ ↩
- “Brachioradial Pruritus as a Result of Cervical Spine Pathology: The Results of a Magnetic Resonance Tomography Study,” October 2011, http://www.ncbi.nlm.nih.gov/pubmed/21641675 ↩
- “Clinical, Epidemiological and Therapeutic Profile of Patients with Brachioradial Pruritus in a Reference Service in Dermatology,” July 2016, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4999125/ ↩