Activated coagulation cascade has a role in urticaria pathogenesis, characterized by high plasma D-dimer, a marker of fibrinolysis. Levels correspond to high urticaria activity score (UAS) and poor treatment outcome.

The present study compared quantitative plasma D-dimer levels and coagulation parameters of 100 (male:female ratio 1:3) Indian patients with chronic spontaneous urticaria and age- and gender-matched healthy controls. The clinicoepidemiologic features of chronic urticaria were also compared among patients with normal (≤0.2 mg/L) and raised (≥0.3 mg/L) plasma D-dimer levels.

Plasma D-dimer levels were significantly elevated in 23% patients and 4% controls. Prothrombin time and activated partial thromboplastin time were found to be significantly higher in 63% and 5% patients, respectively, compared to 58% and 1% of controls, respectively. Eighteen of 72 (25%) patients with high UAS7 of ≥16-42 were compared with 5 of 28 (17.8%) patients with UAS7 of ≤15. About 86.9% patients with elevated plasma D-dimer levels were noted as having one or more additional systemic symptoms compared to 81.8% patients with normal plasma D-dimer levels.

The study revealed that a subset of patients with chronic urticaria have increased levels of plasma D-dimer and exhibit higher UAS7 and systemic symptoms that could affect long-term prognosis and treatment choices.

Source: Chauhan S, Mahajan VK, Mehta KS, et al. Clinicoepidemiologic Features of Chronic Spontaneous Urticaria in Patients with Elevated Plasma D-Dimer Levels versus those without It: A Case-Control Cross-Sectional Study of 100 Indian Patients. Indian Dermatol Online J. 2019 Nov 1;10(6):632-638.