Spontaneous allergic autocytotoxicity of white blood cells was assessed in six patients with bronchial asthma and 18 normal control volunteers. The observed alterations in non-primed white blood cell membrane were revealed as an increased uptake of trypan blue exclusion dye, an indicator of cell death. The phenomenon of spontaneous allergic autocytotoxicity might be associated with increased permeability of the white blood cell membrane leading to enhanced releasability of chemical mediators of anaphylaxis, which probably bypasses immunoglobulin E mechanisms and T suppressor cell intervention. Of six patients with bronchial asthma, three were sensitive to wheat, two had cows milk sensitivity, and one had corn sensitivity. When white blood cells of these patients were studied in the direct allergic autocytotoxicity assay, augmentation of spontaneous allergic autocytotoxicity by specific food antigens was observed. Two of the patients were professional sports coaches. It is plausible to suggest that increased membrane permeability, presumably indicating increased releasability (i.e., for histamine), may be associated with a low membrane threshold for physical trauma expressed in exercise-induced anaphylaxis syndromes.