BACKGROUND: Anaphylaxis is a potentially fatal immediate-type reaction and intense effort may be required to identify the allergen responsible. In some cases, a "hidden" allergen may be responsible that is not apparent in spite of careful clinical assessment. OBJECTIVES: This report describes the assessment of two cases of anaphylaxis in which a search for an allergen was initially not conclusive and the diagnosis of idiopathic anaphylaxis was considered. METHODS: Two patients were evaluated by various physicians for anaphylaxis with no clear indication of a responsible allergen. Persistence in evaluation led to the identification of the allergen responsible. RESULTS: In two health care workers latex was identified as the "hidden" cause of anaphylaxis. This allergen had not been considered in either case in initial evaluations. Neither patient has had a recurrence of anaphylaxis since latex was identified as the cause of anaphylaxis. CONCLUSIONS: Although latex is widely recognized as a cause of anaphylaxis, it can still be unrecognized in some cases of recurrent anaphylaxis. Latex must be considered as a "hidden" cause of anaphylaxis, particularly in health care workers.
BACKGROUND: Anaphylaxis is a potentially fatal immediate-type reaction and intense effort may be required to identify the allergen responsible. In some cases, a "hidden" allergen may be responsible that is not apparent in spite of careful clinical assessment. OBJECTIVES: This report describes the assessment of two cases of anaphylaxis in which a search for an allergen was initially not conclusive and the diagnosis of idiopathic anaphylaxis was considered. METHODS: Two patients were evaluated by various physicians for anaphylaxis with no clear indication of a responsible allergen. Persistence in evaluation led to the identification of the allergen responsible. RESULTS: In two health care workers latex was identified as the "hidden" cause of anaphylaxis. This allergen had not been considered in either case in initial evaluations. Neither patient has had a recurrence of anaphylaxis since latex was identified as the cause of anaphylaxis. CONCLUSIONS: Although latex is widely recognized as a cause of anaphylaxis, it can still be unrecognized in some cases of recurrent anaphylaxis. Latex must be considered as a "hidden" cause of anaphylaxis, particularly in health care workers.