A 39-year-old man presented with an asymmetric distal weakness and loss of sensitivity sequentially affecting both lower extremities and the left upper limb. Nerve conduction studies showed a multifocal sensory and motor axonal neuropathy, and a pseudo-conduction block of the right fibular nerve, the whole being consistent with a mononeuropathy multiplex. An uncommon etiology was found after an extensive workup. Axonal loss was severe, with only partial response to treatment with corticosteroids and IV immunoglobulins.