What is the diagnosis and treatment for a patient with pruritus (itching sensation) on the occipital area, described as a deep itchiness feeling as if it's internal?

Diagnosis: Neuropathic Pruritus (Likely Notalgia Paresthetica)

This patient's description of "deep itchiness" in the occipital area that feels internal is classic for neuropathic pruritus, most likely representing a localized nerve compression or small fiber neuropathy affecting the occipital region. 1

Key Diagnostic Features

The patient's specific description is pathognomonic for neuropathic itch:

• "Deep" or "internal" sensation distinguishes neuropathic from inflammatory pruritus 1
• Localized to occipital area suggests nerve compression in the corresponding dermatome 1
• Sensory symptoms like burning, tingling, or stinging may accompany the itch (ask specifically about these) 1

Differential Diagnosis to Rule Out

Before confirming neuropathic pruritus, examine for:

• Primary skin lesions (erythema, scaling, excoriation) - their presence suggests inflammatory dermatosis rather than neuropathic cause 2, 3
• Cervical spine pathology - nerve root compression from degenerative disease or disc herniation can cause occipital neuropathic itch 1
• Postherpetic neuralgia - history of shingles in the occipital distribution 1
• Small fiber neuropathy - associated with diabetes, HIV, sarcoidosis, or neurofibromatosis 1

Diagnostic Workup

Initial Assessment

• Detailed neurological examination of the occipital region looking for sensory changes, trigger points, or allodynia 1
• Cervical spine imaging if mechanical compression is suspected 1
• Skin biopsy to confirm small fiber neuropathy if diagnosis remains uncertain (shows reduced intraepidermal nerve fiber density) 1, 4

Laboratory Testing (Only if Systemic Disease Suspected)

• Complete blood count, comprehensive metabolic panel, thyroid function tests 5, 2
• Fasting glucose or HbA1c to exclude diabetes 1
• HIV serology if risk factors present 1

Do not perform extensive systemic workup unless clinical features suggest generalized disease - localized occipital pruritus with "deep" quality is neuropathic until proven otherwise. 1

Treatment Algorithm

First-Line: Topical Neuropathic Agents

Start with topical menthol 0.5% or pramoxine applied 2-3 times daily to the affected area - these provide immediate symptomatic relief by modulating nerve signaling. 6, 2

Alternative topical options:

• Lidocaine 5% patches or cream applied to occipital area 2
• Capsaicin cream (warn about initial burning sensation) 2

Second-Line: Systemic Neuromodulators

If topical therapy fails after 2 weeks:

Gabapentin 300 mg at bedtime, titrate up to 900-3600 mg daily in divided doses - highly effective for neuropathic pruritus. 7, 6, 2

Alternative:

• Pregabalin 25-75 mg at bedtime, titrate to 150 mg daily 7, 6

Third-Line: Antidepressants

If gabapentinoids are ineffective or not tolerated:

• Mirtazapine 7.5-15 mg at bedtime (sedating, helps with sleep disruption) 7, 6
• Paroxetine 10-20 mg daily or sertraline 50-100 mg daily 7, 6, 2

Adjunctive Therapy

Combine topical anti-inflammatory with neuropathic agents if any secondary inflammation from scratching:

• Triamcinolone 0.1% ointment applied twice daily for up to 2 weeks 2
• Hydrocortisone 2.5% cream for milder cases 6, 2

Critical Pitfalls to Avoid

• Do not treat with antihistamines alone - they are ineffective for neuropathic pruritus and may cause sedation/cognitive impairment, especially in elderly patients 4, 6
• Avoid gabapentin if hepatic disease is present - it can worsen hepatic encephalopathy 7, 4
• Do not use high-potency topical steroids long-term - limit clobetasol to 2 consecutive weeks maximum if used 8
• Refer to neurology if progressive neurological symptoms develop or if standard treatments fail after 8-12 weeks 1

Expected Timeline

• Topical agents: Symptom improvement within 1-2 weeks 6
• Gabapentin/pregabalin: Therapeutic effect may take 2-4 weeks at adequate doses 2
• Antidepressants: Full effect requires 4-6 weeks 2

If no improvement after 12 weeks of appropriate therapy, reconsider diagnosis and refer to dermatology or neurology for further evaluation. 1