Review Article
Ichiro Katayama, Saki Matsu
Abstract
Background: Much attention has been paid to activation of the blood coagulation cascade during urticaria attacks. Elevated levels of plasma D-dimer and prothrombin fragment 1+2 have been reported. The final product of the coagulation cascade, thrombin, may induce mast cell degranulation, complement fragmentation, or platelet-activating factor expression. However, the involvement of platelets in urticaria is poorly understood. Methods: We examined the relationship between disease activity and plasma levels of platelet factor IV, β-thromboglobulin, D-dimer, and prothrombinfragment (Fr) 1+2 in 23 patients with chronic urticaria. Results: We observed elevated plasma levels of platelet factor IV (13/23) and β-thromboglobulin (15/23) in patients with chronic urticaria that returned to normal after anti-histamine therapy. Platelet re-activation was observed in recurrent urticaria. Some cases showed clinical response to anti-platelet therapy or Helicobacter pylori decolonization in combination with anti-histamine treatment. Conclusions: Platelet activation is a possible indicator of disease activity in chronic urticaria. Platelet-derived factors with or without blood coagulation products might induce mast cell degranulation in chronic urticaria.