Chronic idiopathic angioedema: a single center experience

OBJECTIVE: Chronic idiopathic angioedema (CIA) is defined as three or more episodes of angioedema in a period of > 6 months without a clear etiology. In the study, we tried to explore clinical and laboratory characteristics of patients with CIA unaccompanied by urticaria. METHODS: We retrospectively reviewed clinical and laboratory characteristics of 1238 patients with chronic urticaria and/or angioedema referred to our allergy clinic. RESULTS: Eight hundred and forty-one (67.9%) subjects had chronic urticaria without angioedema (CU Group), 323 (26.1%) had both urticaria and angioedema (CU + CA group), and 74 (5.9%) had chronic angioedema without urticaria (CA). In 29 (39.2%) cases of CA, no etiologic factor of angioedema was discovered, thus the patients were defined as having chronic idiopathic angioedema (CIA Group). Twenty-two (75.8%) subjects had antihistamine-responsive CIA and seven (24.1%) had antihistamine-unresponsive CIA. There were no statistically significant differences in clinical (except of urticarial eruptions) and laboratory characteristics between CU, CA + CU, and CIA groups. Antihistamine responsive and antihistamine-unresponsive CIA groups had no distinguishable clinical or laboratory features. CONCLUSIONS: We suppose that CIA, at least its antihistamine-responsive form, represents a rare form of chronic spontaneous urticaria. The reasons why in CIA there are no other clinical signs of mast cell/basophil activation, such as pruritus, urticarial, and dermatographism, are largely unknown and have to be elucidated in future studies.