Vasculitic neuropathy in a patient with hereditary C1 inhibitor deficiency.

OBJECTIVE

To report the clinical, pathological, and mutational features of hereditary C1 inhibitor (C1INH) deficiency as a cause of isolated vasculitic neuropathy.

PATIENT: A 35-year-old woman with sensorimotor mononeuritis multiplex and facial palsy.

RESULTS

The sural nerve biopsy results showed a decrease of myelinated fibers with axonal degeneration and severe hypersensitivity vasculitis, with deposition of C1q on vessel walls. Mutational analysis of the C1INH gene found a new mutation, a heterozygous 2-base pair deletion in exon 8. The patient was treated with plasmapheresis and intravenous methylprednisolone, followed by oral prednisolone, which resulted in marked improvement.

CONCLUSION

Hereditary C1INH deficiency should be included in the differential diagnosis of nonsystemic vasculitis neuropathy.