Basophil Activation Test with Food Additives in Chronic Urticaria Patients
A 37-year-old woman visited the outpatient allergy clinic because of urticaria. She suffered from recurrent generalized urticaria, rash, and facial angioedema. She complained that the urticarial aggravation occurred particularly when eating high-seasoned, spicy, or Chinese foods. Previously, she had been treated for allergic rhinitis and also had experienced severe urticaria with a generalized rash after taking non-steroidal anti-inflammatory drugs (NSAIDs). Peripheral eosinophil counts and serum total IgE in her blood were 97.2/µL and 97 kU/L, respectively. T4 and thyroid stimulating hormone were also within normal range. A skin prick test showed weakly positive reactions (wheal size ≥3 mm but allergen/histamine ratio <1) to silk worm pupa, herring, cabbage, celery and walnut; however, none of them provoked urticaria in the history. In the BAT, a total of 18.7% of basophils were activated after stimulation with MSG (); however, the other 14 additives did not induce significant basophil activation, compared to the negative control (1.3%).