Severe acute urticaria is associated with elevated plasma levels of D-dimer

Evaluation of the disease severity of acute urticaria (AU) is essential for adequate treatment of patients. However, there are no reliable biomarkers for such an evaluation. In our department, we observed patients with severe AU having elevated plasma D-dimer levels. Thus, the objective of this study was to investigate the elevated D-dimer levels in patients with severe AU in more detail. One hundred and thirty-nine hospital patients diagnosed with severe AU were enrolled. Clinical laboratory data were collected from electronic medical records. One hundred and seventeen of the patients presented with elevated plasma D-dimer levels. Compared to the normal group, the elevated group had a significantly higher proportion of patients who were female, younger, febrile, and had a shorter prehospital time (P < 0.05). Univariate regression analysis showed that neutrophil percentage, C-reactive protein (CRP), and lactate dehydrogenase (LDH) levels increased as D-dimer levels increased, while prehospital time showed the opposite trend. Multiple regression analysis was used to estimate the simultaneous effects of CRP and LDH on D-dimer levels. Patients who responded to additional antibiotic treatment had higher levels of D-dimer. The group with highly elevated D-dimer levels required a higher maximum dose of daily glucocorticoids (GCs) to control the symptoms of AU. In conclusion, patients with severe AU might have elevated plasma D-dimer levels, which are positively correlated with CRP and LDH levels. Patients with severe AU with dramatically elevated D-dimer levels might need a higher dose of daily GCs and antibiotics to relieve symptoms. D-dimer may be a reasonable marker to evaluate the severity of AU and guide treatment.