Pruritus in neuromyelitis optica spectrum disorders and multiple sclerosis.

Purpose: Differential diagnosis between neuromyelitis optica spectrum disorders (NMOSD) and multiple sclerosis (MS) at early stage remains challenging at present. Pruritus is reported as a common or specific feature in NMOSD with serum aquaporin-4 immunoglobulin G antibodies (AQP4-IgG). We aim to verify whether pruritus can help in distinguishing NMOSD from MS.

Methods: We retrospectively reviewed the medical records of consecutive cases of NMOSD and MS patients, demographic data, clinical features, whether or not had pruritus, serum AQP4-IgG status and magnetic resonance imaging (MRI) results.

Results: 21.0% (22/105) of NMOSD patients and 2.1% (2/96) of MS patients reported pruritus during disease course (p < 0.01). 20.5% (18/88) of AQP4-IgG positive and 23.5% (4/17) of AQP4-IgG negative NMOSD patients reported pruritus during disease course (p = 0.775). 12.4% (13/105) of NMOSD and 1.0% (1/96) of MS patients reported pruritus at the first attack episode of disease (p < 0.01). 20.0% (21/105) of NMOSD and 1.0% (1/96) of MS patients reported pruritus at the first and second attack episodes of disease (p < 0.01).

Conclusion: Pruritus is a common and relatively specific feature in either AQP4-IgG positive or negative NMOSD. Pruritus occurs more frequently in NMOSD than MS, which may help in distinguishing NMOSD from MS, especially at early stage.