Casualties from a junior-senior high school during the Persian Gulf War: toxic poisoning or mass hysteria?

Mass hysteria is a bizarre and uncommon epidemic phenomenon. The usual victims are adolescent females and school settings are frequent. The epidemics are characterized by the rapid onset of a constellation of symptoms and signs which resolve quickly in the absence of abnormal laboratory results and physical findings that confirm a specific organic cause. It is common, however, for unexpected laboratory results to cause confusion and promote controversy about suspected etiologies. These outbreaks are often noted to be associated with periods of uncertainty and social stress. We describe an epidemic involving the explosive onset and rapid resolution of a constellation of symptoms that sent 17 seventh and eighth grade students and four teachers to the emergency department of a hospital after an apparent toxic gas exposure. Mildly elevated carboxyhemoglobin levels (for nonsmokers) in some patients raised concern that there had been exposure to excessive levels of carbon monoxide. Although no specific unusual stress could be identified at the school, the event took place 3 1/2 weeks after the beginning of the Persian Gulf War.