A study published in the current issue of Psychotherapy and Psychosomatics indicates that psychological fever may have some specific biologic characteristics.
Psychogenic fever is a psychosomatic disease especially seen in adolescents and young adults. The underlying mechanism for adolescent patients developing such high temperatures is not fully understood. Animal studies demonstrated that psychological stress-induced hyperthermia is mediated via mechanisms different from those involved in fever due to infections, which requires proinflammatory mediators, and that the sympathetic nervous system, especially β3-adrenoceptor-mediated nonshivering thermogenesis, plays an important role in the development of psychological stress-induced hyperthermia. If this is the case with humans, psychogenic fever patients may manifest a heightened sympathetic response to stress.
Measuring the cardiovascular response to orthostatic stress is a noninvasive method for evaluating the stress-induced autonomic response.
To evaluate whether adolescent patients would show a higher HR response than adult patients as well as healthy adolescents, 24 adolescent patients with psychogenic fever (mean age 15.5 ± 0.3 years, 6 males) who were referred to our department and 24 age- and gender-matched healthy subjects (mean age 15.5 ± 0.3 years, 6 males) underwent orthostatic testing. Psychogenic fever was diagnosed based on the following criteria: (1) there were no inflammatory signs or endocrine diseases, (2) the fever developed during a psychosocially stressful situation, which was assessed by a diagnostic interview, and (3) their high temperature was not normalized by cyclooxygenase inhibitors or adrenocortical steroids but by psychotropic drugs or psychotherapy.
Results showed that increase in HR after standing was significantly higher in psychogenic fever patients than in healthy subjects across time, whereas there was no difference in either ΔSBP or ΔDBP between the two groups. The number of subjects who met the criteria of POTS was higher in psychogenic fever patients (n = 9, 38%) than healthy subjects (n = 1, 4%, p = 0.01).. When comparing the findings of this study with our previous study conducted in adults [7], the ΔHR of adolescent patients was significantly greater than that of adult patients (16.7 ± 1.4 bpm, p = 0.005). The maximal value of ΔHR after standing (ΔHRmax) decreased with age in both the patient and control groups.
In conclusion, this study demonstrated that psychogenic fever patients, both adolescents and adults, show a heightened HR response to orthostatic stress compared with healthy subjects. This phenomenon is more evident in adolescent patients than in adult patients.