The clinical characteristics and outcome between the W+ and the W– groups*.

*Presence or absence of water immersion of the affected limbs before the onset.†Odds ratio.‡Confidence interval.§Underlying medical illness: including diabetes mellitus, liver cirrhosis, chronic renal disease, malignancy, autoimmune disease, alcoholism, long-term steroid or immunosuppressive therapy, human immunodeficiency virus infection.¶Iintensive care unit.**Analyzed by student’s t = test.