Increased D-dimer and fibrin degradation product levels as potential indicators for evaluating infection-related acute urticaria: a case-case-control study.

About 20% of world population suffer from acute urticaria at some stage in their lives. Recent studies showed coagulation dysfunction in chronic urticaria. The involvement of coagulation changes in acute urticaria remains unclear. Fifty-eight acute urticaria patients were enrolled in this study and divided into two groups (referred to throughout as infection-related and infection-unrelated acute urticaria). The routine laboratory parameters including coagulation tests between the two groups were compared. The correlation between coagulation tests and CRP at acute phase was also assessed. Dynamic change of routine coagulation test results at acute phase and resolving phase was compared. The potential performance of coagulation for infection indication was tested. We found D-dimer, fibrin degradation product (FDP), and fibrinogen (Fg) increased in the acute phase of infection-related acute urticaria patients. D-dimer, FDP, Fg, and APTT are positively correlated with CRP in the acute phase. D-dimer and FDP decreased in the resolving phase of infection-related acute urticaria patients. Higher D-dimer (> 0.48 mg/L) and FDP (> 3.84 mg/L) may indicate infection-related acute urticaria. In conclusion, in acute urticaria with low venous thromboembolism risk, D-dimer level and dynamic change can be potentially used for the infection-related clinical practice management.