Abnormal sweating and "skin flushing" as possible predictive factor for treatment related fluctuations in Guillain-Barré syndrome: a case series and a review of the literature.

Treatment related fluctuations (TRFs) in Guillain-Barré Syndrome (GBS) are described as one or more episodes of deterioration manifesting within two months after disease onset and following an initial improvement or stabilisation after treatment. They may be encountered in 8% to 16% of patients, but currently predictive factors of TRF occurrence and severity are poorly known. To this end, we evaluated the frequency and clinical features of TRFs in a cohort of GBS patients admitted to the Neurological unit of Sant'Andrea Hospital (La Spezia, Italy) from January 1st, 2003 to December 31st, 2017. Among the 98 GBS collected patients, five (5.1%) developed a TRF during disease course. Consistently with the literature, the majority of our GBS patients who developed a TRF did not report a preceding diarrhoea, had a predominant proximal weakness and all of them had sensory disturbances at the clinical onset. Interestingly, 80% of our TRF patients manifested since GBS onset an autonomic dysfunction with abnormal sweating and a peculiar 'skin flushing' in face, neck and chest. Two patients developed respiratory insufficiency at the TRF time, and they both died. We would advise to pay attention to GBS patients with particular 'skin flushing' in face, neck and chest and abnormal sweating, because these findings could be a red flag for TRF.