Coronary spasm and allergy. Retrospective study of the incidence of allergic history in patients with variant angina.

Despite a large number of papers concerning coronary spasm, its mechanism still remains unsolved. Several cases have been reported in which coronary spasm was triggered by allergy. Since histamine is one of the causative substances released in allergic reactions, we speculated on some involvement of an allergic mechanism in the pathogenesis of coronary spasm. We retrospectively examined by questionnaire the incidence of allergic history in patients with variant angina (n = 47) and compared it with that in patients with non-ischemic heart diseases (n = 83). We could not find any relationship between coronary spasm and allergy. Furthermore, we have not experienced any case in which myocardial ischemia was provoked by an allergic reaction. Accordingly, allergy could not be a major cause of coronary spasm in our present experience.