Abstract
Acute hyperhidrosis is characterized by excessive sweating. In the absence of other symptoms, the symptoms of sweating alone are often benign and may be ignored by patients and clinicians. Rarely, hyperhidrosis may be a harbinger of an underlying severe disease. Autonomic nervous system dysfunction leading to hyperactivity of the sympathetic nervous system can result in excessive sweating. This case report is about a gentleman who presented with acute hyperhidrosis, a symptom of autonomic dysfunction, which turned out to be a relapse of anti-leucine-rich glioma-inactivated 1 (LGI1) antibody encephalitis. This case adds to the existing literature on cases of anti-LGI-1 encephalitis, a rare form of autoimmune encephalitis, and its varied clinical manifestations. It serves as a reminder to consider a wide range of differentials in patients who present with a seemingly nonspecific complaint such as excessive sweating.