Multiple chemical sensitivity (MCS) is a disorder of unknown etiology with no effective treatment. Many clinicians accept that a diagnosis of somatic symptoms disorder (SSD) is an appropriate diagnostic category for MCS. We found that administration of levetiracetam improved recurrent symptoms of MCS in a patient. A 23-year-old female presented with recurrent multiple symptoms of musculoskeletal, airway or mucous membrane, heart/chest-related, gastrointestinal, cognitive, affective, neuromuscular, head-related, and skinrelated induced by exposure to diesel or gas engine exhaust, tobacco smoke, insecticide, gasoline, paint or paint thinner, cleaning products, fragrances, tar or asphalt, nail polish or hairspray, and new furnishings. Gastrointestinal, cognitive, and skin-related symptoms were precipitated by some food additives. She suffered partial seizures from the age of 17 years, and was diagnosed with right parietal lobe epilepsy. Administration of levetiracetam (250 mg/day) eliminated her MCS symptoms. Levetiracetam reduces the release of presynaptic neurotransmitter including glutamate by binding to presynaptic vesicle protein. A recent study established the presence of glutamatergic overactivation in somatization disorder, a form of SSD. Our case may indicate that a subset of patients with SSD have glutamatergic overactivation, which levetiracetam can normalize
