Aim: Anaphylaxis is a systemic allergic reaction that potentially causes death. Most anaphylactic reactions are uniphasic, but some cases may be biphasic or protracted. However, these clinical epidemiology concepts are unfamiliar in Japan. Therefore, we have investigated the incidences and characteristics of patients with biphasic and protracted anaphylaxis. Methods:We retrospectively evaluated patients with anaphylaxis in a single emergency medical center located in Yokohama, Japan from April 2009 to March 2012. We analyzed the incidences and characteristics of patients with biphasic and protracted anaphylaxis who needed to be admitted.Results: A total of 253 patients were diagnosed with anaphylaxis and 114 patients needed to be admitted. Of the 114 patients, 103(90.4%) were uniphasic, 7 (6.1%) were biphasic and 4 (3.5%) were protracted anaphylaxis. The most common antigens were foods and drugs. The median onset of a biphasic reaction was 8 h and dermatologic symptoms were mostly observed. Regarding severity, mild symptoms were seen in four cases, similar symptoms to the initial reaction were seen in two cases, and only one case was severe. The duration of protracted anaphylaxis varied from 2 to 8 days. Conclusion:The incidence of biphasic and protracted anaphylaxis in inpatients was 6.1% and 3.5%, respectively. The median onset of biphasic reaction was 8 h, and most symptoms were mild or similar to the initial reaction. We suggest that patients with anaphylaxis need an 8-h and ideally a 24-h observation period in order to monitor possible biphasic reactions. The duration of protracted anaphylaxis was up to 8 days.

The present results further support the hypothesis that the DUP affects QOL, social functioning, and cognitive function over the course of illness, especially in patients with an insidious onset. Effective strategies for detecting and caring for individuals with insidious onset early during the course of schizophrenia will be essential for achieving a full patient recovery.

Twin studies of psychiatric disorders such as schizophrenia and autism spectrum disorder have employed epidemiological approaches that determine heritability by comparing the concordance rate between monozygotic twins (MZs) and dizygotic twins. The basis for these studies is that MZs share 100% of their genetic information. Recently, biological studies based on molecular methods are now being increasingly applied to examine the differences between MZs discordance for psychiatric disorders to unravel their possible causes. Although recent advances in next-generation sequencing have increased the accuracy of this line of research, there has been greater emphasis placed on epigenetic changes versus DNA sequence changes as the probable cause of discordant psychiatric disorders in MZs. Since the epigenetic status differs in each tissue type, in addition to the DNA from the peripheral blood, studies using DNA from nerve cells induced from postmortem brains or induced pluripotent stem cells are being carried out. Although it was originally thought that epigenetic changes occurred as a result of environmental factors, and thus were not transmittable, it is now known that such changes might possibly be transmitted between generations. Therefore, the potential possible effects of intestinal flora inside the body are currently being investigated as a cause of discordance in MZs. As a result, twin studies of psychiatric disorders are greatly contributing to the elucidation of genetic and environmental factors in the etiology of psychiatric conditions.

No abstract