Purpose of review: This study aimed to review important hidden causes of anaphylaxis in ingestants, non-ingestants, and uncommon settings.
Recent findings: Multiple new and elusive causes of anaphylaxis have been described over the past 35 years. Further research is required to identify the epidemiology, pathophysiology, and clinical impact of these hidden causes. Although these culprits should be considered in the appropriate clinical scenarios, many remain exceedingly rare.
Keywords: Allergy; Anaphylaxis; Concealed; Hidden; Uncommon; Unexpected.