10/1/03 Urticaria and angioedema - clinical aspectsSummaryUrticaria (Urt) is a common disorder, with 20% of the population manifesting at least one episode during a lifetime. Nettis et al of the Univ. of Bari in Italy recently reviewed some clinical and etiologic aspects of Urt and associated angioedema (Ang) seen by their group. Based on their study of 562 consecutive adult patients diagnosed with Urt and/or Ang, they found a higher number of females than males (384/178), history of atopy in the patient (24%) and or family (35%). Physical urticaria was present in 14%, contact urticaria in 1%, and urticarial vasculitis present in 0.5%. Ang was present without Urt in 9%. Of those with Urt, 10% had acute Urt, 73% had chronic Urt, and 17% episodic Urt. After thorough evaluation for etiologic factors in the Urt/Ang, an immune basis was diagnosed in 9%, a non-immune cause in 6% and Urt secondary to infections diagnosed in 3%. In the rest of the patients (82%) the Urt was considered idiopathic. In patients treated with antihistamines, 54% showed a significant improvement. Reference Brit J Dermatol 2003; 148:501-6 Editor’s Comments The overall clinical profile in this sizable population of patients with Urt/Ang is fairly similar to that reported previously by others. I have real questions about the strength of the evidence to support a diagnosis of a) immune-mediated and b) infection-mediated chronic Urt. Most expert investigators of Urt feel that there is little evidence for chronic infection as a cause of chronic Urt. (An exception may be infection with H. pylori about which there is still considerable debate). Another unsettled area is the relationship of chronic Urt to thyroid autoimmunity. Most investigators have found an increased incidence of thyroid autoantibodies in chronic Urt patients. However, the pathogenic significance of this finding is still uncertain. There is evidence of likely pathogenic autoimmune mechanism in some cases of chronic Urt. As discussed in previous reviews in this AADMC website, increased serum levels of autoantibodies against the alpha chain of the Fc epsilon RI receptor on mast cells and basophils are present in 30-40% of those with chronic idiopathic Urt. Antibodies against IgE itself are present in a small percentage of chronic Urt patients. The stimulus for these autoimmune responses is still not defined.
|
