[Blood-injection-injury phobia: Physochophysiological and therapeutical specificities]

Seventy-five percent of patients with blood-injection-injury phobia (BII-phobia) report a history of fainting in response to phobic stimuli. This specificity may lead to medical conditions remaining undiagnosed and untreated, incurring considerable cost for the individual and society. The psychophysiology of BII-phobia remains poorly understood and the literature on effective treatments has been fairly sparse. Aims of the systematic review: to synthesize the psychophysiology of BII-phobia and to propose a systematic review of the literature on effectiveness of different treatments evaluated in this indication.

Firstly, the most distinct feature of the psychophysiology of BII-phobia is its culmination in a vasovagal syncope, which has been described as biphasic. The initial phase involves a sympathetic activation as is typically expected from fear responses of the fight-flight type. The second phase is characterized by a parasympathetic activation leading to fainting, which is associated with disgust. Subjects with syncope related to BII-phobia have an underlying autonomic dysregulation predisposing them to neurally mediated syncope, even in the absence of any blood or injury stimulus. Many studies report that BII-phobic individuals have a higher level of disgust sensitivity than individuals without any phobia. Secondly, behavioral psychotherapy techniques such as exposure only, applied relaxation, applied tension, and tension only, have demonstrated efficacy with no significant difference between all these techniques. The disgust induction has not improved effectiveness of exposure.

We have explained the psychophysiology of BII-phobia, the understanding of which is required to study and validate specific techniques, in order to improve the prognosis of this disorder, which is a public health issue.