When the Skin Speaks Before the Nerves: A Case of Cutaneous Vasculitis Presenting as Asymmetric Neuropathy

Vasculitic neuropathy represents a challenging diagnostic entity due to its heterogeneous clinical presentation and multi-system involvement. We report the case of a 59-year-old woman who initially presented with erythematous rashes progressing to palpable purpura over both lower limbs, abdomen, and forearms, followed by the development of asymmetric motor and sensory neuropathy manifesting as right foot drop and distal sensory loss. The onset of neuropathy occurred three days after the appearance of cutaneous lesions, raising clinical suspicion of an underlying small-vessel vasculitis. Laboratory workup revealed nephrotic-range proteinuria with preserved renal morphology on ultrasonography. Autoimmune profiling showed ANA 1+, while ANCA and complement levels were normal. Nerve conduction studies demonstrated sensory-predominant motor polyradiculoneuropathy with primary demyelination and secondary axonal loss. Skin biopsy confirmed leukocytoclastic vasculitis, and nerve biopsy showed chronic axonal neuropathy with vascular changes indicative of vasculitic neuropathy. MRI of the lumbosacral spine ruled out compressive etiologies. This case highlights the importance of early recognition of cutaneous and neurological manifestations of vasculitis, as timely biopsy-driven diagnosis is essential for preventing progressive neurological damage.