Features:
(1) relatively severe symptoms of sudden onset in a number of people, particularly after leaving the purported source of the exposure
(2) transmission of illness by sight or sound
(3) symptoms occur after learning of suspected exposure or seeing someone else with illness
(4) rapid spread with rapid remission
(5) diversity of symptoms without physicals signs or laboratory findings (absence of objective medical findings)
(6) relapse of symptoms when affected persons congregate
(7) absence of significant environmental findings
(8) absence of the usual symptoms expected from exposure to the alleged contaminant or source material
(9) higher attack rate among females than males when the population at risk includes both sexes
(10) benign morbidity with lack of sequelae
(11) occasionally may show conversion symptoms (loss or alteration of physical functioning, not under voluntary control) that cannot be explained by any physical disorder or known pathophysiologic mechanism
(12) affected persons may strongly defend their beliefs and refuse any alternative explanation for their symptoms
Frequent complaints:
(1) headache
(2) faintness
(3) dizziness
(4) nausea
(5) chest tightness
(6) difficulty breathing
(7) irritation of eyes, nose or throat
(8) weakness
(9) numbness
(10) palpitations
(11) vague pains in different parts of the body
(12) difficulty with concentration and/or memory
Differential diagnosis:
(1) sick building syndrome
(2) true chemical or biological exposure
Management:
(1) remove affected persons from stimulating environment
(2) separate the group as quickly as possible and try to keep it from regathering
(3) do not downplay or minimize the patient's concerns
(4) try to identify anyone with a true toxic, allergic or infectious disease
(5) emphasize the certainties of the situation and provide information as needed
(6) a mild tranquilizer may be considered during the acute episode
(7) give explicit follow-up instructions, with actions to take if the symptoms recur
(8) if the diagnosis is in doubt, perform a careful environmental survey
(9) if the diagnosis is likely, try to address the anxiety and depression
