What is the treatment approach for neurological pruritus?

Treatment of Neuropathic Pruritus

Patients with neuropathic pruritus should be referred to the relevant specialist (neurology or dermatology) for treatment, and gabapentin is the first-line systemic agent for symptomatic relief. 1

Initial Diagnostic Approach

Following detailed history and examination, patients with suspected neuropathic pruritus require targeted investigation only when clinically indicated—not routine extensive neurological workup. 1

Key diagnostic considerations:

• Consider skin biopsy to confirm small fiber neuropathy if suspected, though this is optional and not routinely required. 1
• Imaging (spinal X-ray or MRI) should be pursued when history suggests nerve root compression, radiculopathy, or central lesions. 2
• Look for dermatomal distribution patterns that correlate with vertebral pathology, particularly C5-C7 levels which are commonly affected. 2

Pharmacological Treatment Algorithm

First-Line: Gabapentin

Gabapentin 300-1200 mg daily is the primary systemic treatment for neuropathic pruritus, with 85.7% of patients achieving complete or near-complete resolution. 2, 3

• Start at 300 mg daily and titrate upward based on response. 2
• Pregabalin is an alternative anticonvulsant option. 3
• These agents work by inhibiting neuronal excitability in the central nervous system. 3, 4

Topical Therapies

Local anesthetics and capsaicin serve as adjunctive topical agents to reduce neuronal excitability at the peripheral level. 3, 5

Additional topical options with some evidence:

• Doxepin (limited to 8 days, 10% body surface area, 12 g daily maximum). 1, 6
• Tacrolimus ointment. 3
• Botulinum toxin A for localized neuropathic itch. 3

Ineffective Agents to Avoid

Antihistamines and corticosteroids lack efficacy in neuropathic itch and should not be used. 3, 5

• These agents target histamine-mediated and inflammatory pathways that are not involved in neuropathic pruritus pathophysiology. 3, 5
• Do not use gabapentin for hepatic pruritus (different mechanism), but it is specifically indicated for neuropathic causes. 1, 6

Physical and Interventional Modalities

Transcutaneous electrical nerve stimulation (TENS) provides non-pharmacological relief in selected cases. 3

Other physical therapy options:

• Physical therapy for nerve decompression and mobility. 3
• Phototherapy has limited role but may be considered. 3
• Acupuncture can be considered individually, though evidence is not robust for first-line recommendation. 6

Surgical Intervention

Surgery is indicated for structural lesions causing neuropathic itch: spinal/cerebral masses, abscesses, hemorrhagic stroke, or severe entrapment neuropathies requiring decompression. 3

• Surgical decompression may provide definitive relief when nerve compression is the underlying cause. 3
• This is the obvious choice when imaging reveals surgically correctable pathology. 3

Psychosocial Support

Behavioral interventions including education, relaxation techniques, cognitive restructuring, and habit reversal training should be incorporated for distressed patients. 1

• Patient support groups can be beneficial. 1
• Referral to liaison psychiatry or psychology may help in individual cases. 1
• Chronic neuropathic pruritus significantly impairs quality of life and causes psychosocial morbidity in up to one-third of patients. 1

Common Clinical Pitfalls

Do not dismiss generalized symmetric pruritus as non-neuropathic—multilevel symmetric neuropathic pruritus can present as "generalized" itch with bilateral dermatomal distribution. 2

• Look for risk factors: 78.5% of patients with multilevel symmetric neuropathic pruritus are overweight/obese, and all have multiple atherosclerosis risk factors. 2
• Radiographic vertebral changes correlate with cutaneous findings in 85.7% of cases. 2

Recognize that the same neurological diseases causing neuropathic pain can cause itch instead of or in addition to pain. 5

• Shingles (particularly head/neck), small-fiber polyneuropathies, radiculopathies (notalgia paresthetica, brachioradial pruritus), trigeminal nerve lesions, strokes, multiple sclerosis, and cavernous hemangiomas all cause neuropathic itch. 5

Specialist Referral Timing

Refer to neurology or dermatology when neuropathic pruritus is suspected after initial history, examination, and basic investigations. 1

• Collaboration with neurology is essential during initial workup to determine appropriate tests and procedures. 3
• Most patients require symptomatic treatment as causal therapy is often not possible even when the underlying neurological disease is identified. 7