Undifferentiated somatoform idiopathic anaphylaxis: Nonorganic symptoms mimicking idiopathic anaphylaxis

Background: Northwestern University's Division of Allergy and Immunology has had experience with the diagnosis and treatment of more than 350 patients with idiopathic anaphylaxis (IA). In 1992 we reported a group of patients with IA whose presentations mimicked IA, but IA and other organic causes were later excluded. Psychologic factors were suspected as the underlying problem. These patients were classified as IA-variant. Management of these causes was extremely difficult. There was significant morbidity and high and unnecessary costs. Objective: We aim to distinguish the nature of this disease and to highlight the evaluation and treatment of this group of patients. Methods: Their cases are reviewed and reported. Results: Common features included (1) presenting symptoms mimicking IA, (2) no objective findings that correlated with 1, (3) no response to the therapeutic regimen for IA, (4) meeting the Diagnostic and Statistical Manual of Mental Disorders criteria for undifferentiated somatoform disorder, and (5) significant wasted health care expenditure. Conclusions: This group of patients were better defined as having undifferentiated somatoform-IA. An algorithm was proposed to expedite the diagnosis of the disease so that with early recognition of the disease, unwarranted repetitive consultations, tests, and inappropriate therapy can be avoided.