What is the treatment for brachioradial pruritus?

Treatment of Brachioradial Pruritus

Pregabalin is the first-line treatment for brachioradial pruritus, with significant efficacy in reducing symptoms and should be initiated at 25-150mg daily. 1

Understanding Brachioradial Pruritus

Brachioradial pruritus (BRP) is a rare type of neuropathic pruritus characterized by:

• Localization to the dorsolateral forearm, particularly over the brachioradialis muscle
• Symptoms of intense itching, burning, or pain
• Potential etiology involving sun exposure and/or cervical spine disease
• More common in fair-skinned individuals

Treatment Algorithm

First-line Treatments:

1. Neuromodulatory Medications:

   • Pregabalin (25-150mg daily) - Most recent evidence shows significant reduction in itch scores 1
   • Gabapentin (900-3600mg daily) as an alternative 2

2. Topical Treatments:

   • Topical corticosteroids (moderate to high potency) 2
   • Topical doxepin (limited to 8 days, 10% body surface area, maximum 12g daily) 3
   • Menthol-containing preparations may provide relief 3

Second-line Treatments:

1. Combination Therapy:

   • Pregabalin combined with topical ketamine, amitriptyline, and lidocaine cream for refractory cases 1

2. Antihistamines:

   • Non-sedating antihistamines (fexofenadine 180mg, loratadine 10mg, cetirizine 10mg) 2
   • Consider combination of H1 and H2 antagonists for enhanced effect 2

3. Topical Capsaicin:

   • May provide relief but can cause burning sensation 4

For Refractory Cases:

1. Interventional Approaches:

   • Cervical epidural steroid injections if cervical spine disease is present 5

2. Other Systemic Medications:

   • Paroxetine, fluvoxamine, mirtazapine, or naltrexone 2

Special Considerations

Monitoring and Follow-up:

• Regular assessment of symptom improvement
• Monitor for medication side effects:
  • Pregabalin: drowsiness, weight gain 1
  • Topical treatments: skin irritation, allergic contact dermatitis 3, 1

Avoidance Measures:

• Reduce sun exposure, particularly for patients with sun-exacerbated symptoms 4, 6
• Use sun protection when outdoors

Referral Indications:

• Failure to respond to first-line treatments
• Diagnostic uncertainty
• Suspected cervical spine disease requiring imaging or specialist evaluation

Treatment Efficacy and Evidence Quality

The most recent and highest quality evidence from a 2024 retrospective study demonstrates that pregabalin, either alone or in combination with topical agents, provides significant reduction in itch scores for brachioradial pruritus 1. This aligns with earlier case reports showing successful treatment with pregabalin 7.

While the British Association of Dermatologists' guidelines do not specifically address brachioradial pruritus, their recommendations for neuropathic pruritus support the use of gabapentinoids 3, 2.

For patients with suspected cervical spine involvement, addressing the underlying cervical pathology may provide relief, as demonstrated in a case report showing improvement with cervical epidural steroid injections 5.

Common Pitfalls

1. Delayed Diagnosis: BRP is often misdiagnosed, with delays of 2-3 years reported 6
2. Inappropriate Treatment: Using treatments effective for inflammatory dermatoses but ineffective for neuropathic pruritus
3. Overlooking Cervical Spine Disease: Failing to evaluate for cervical pathology in persistent cases
4. Excessive Reliance on Antihistamines: These have limited efficacy in neuropathic pruritus compared to neuromodulatory medications

The neuropathogenic mechanism underlying BRP explains why traditional antipruritic treatments often fail, while neuromodulatory medications like pregabalin and gabapentin show superior efficacy.