Causal Relationship between D-Dimers and Disease Status in Chronic Spontaneous Urticaria and Adjuvant Effect of Oral Tranexamic Acid

INTRODUCTION: Besides autoimmunity, recent studies have reported a role of the coagulation cascade in the pathogenesis of urticaria. However, the real-world data regarding the utility of measuring D-dimer levels in patients chronic spontaneous urticaria (CSU) is missing. This study was done to evaluate the D-dimer levels of CSU patients and study the relationship between raised D-dimer levels and disease severity and treatment response. METHODS: A retrospective chart review of all adult (>18 years) CSU patients was done. Complete clinicodemographic data regarding the disease duration and treatment response were noted. Urticaria activity score over 7 days (UAS7) was used to assess disease severity. RESULTS: Of total 141 patients, D-dimer levels were raised in 46 CSU patients (32.6%) with mean D-dimer levels at baseline in these patients being 329.53 ± 546.94 ng/ml. The proportion of patients with raised plasma D-dimer levels was higher in patients with severe CSU (12.9%, 27.2%, 54.5% in mild, moderate, and severe disease, respectively P < 0.001). No significant differences were found between those with raised D-dimers and those having normal D-dimer levels with respect to age, gender, presence of angioedema, history of atopy, presence of thyroid abnormality, ASST/APST positivity, and serum IgE. CONCLUSION: D-dimer levels parallels the disease severity and can help predict the need for higher dose of antihistamines and second-line therapy in CSU patients.