Increased d-dimer concentration in plasma of patients with severe acute urticaria

Abstract

Conflicts of interest: none declared. SIR, Acute urticaria (AU) is a skin disease frequently caused by different factors (drugs, infections, allergens, psychological stress), although the exact aetiology remains unidentified in many cases. The underlying pathophysiology of AU is mast cell activation.1 The cells release different factors, which exert profibrinolytic and antithrombotic effects.2, 3 Interestingly, it has been demonstrated that the coagulation cascade is activated in chronic urticaria4 and severe exacerbation of the disease is associated with elevated plasma d‐dimer concentration.5d‐dimer is a useful marker, reflecting a potential activation of both the coagulation and fibrinolytic cascade. Considering that changes in the haemostasis system may contribute to the pathogenesis of some types of urticaria, in the present study we measured plasma concentrations of d‐dimer in patients suffering from AU. The study group consisted of 17 consecutive symptomatic patients (10 women and seven men; the median age was 32 years, range 21–42) with AU. The patients were divided into two groups by disease severity according to the criteria defined by Asero et al.5 Ten patients with severe AU were virtually covered by wheals (grade 4, very severe). Seven patients with mild/moderate AU had 1–10 small (< 3 cm in diameter) wheals (grade 1, slight) to 10–50 small wheals or 1–10 large wheals (grade 2, moderate). Five patients suffered from AU caused by nonsteroidal anti‐inflammatory drugs; three patients had AU presumably in the course of acute respiratory tract infection; one suffered from AU and concomitant urinary tract infection treated with antibiotics (amoxicillin). In the remaining eight, the reasons for AU were unidentified. No patient had a history of chronic urticaria. The patients had not taken anti‐urticarial drugs. Blood for analysis was taken within 24 h from the onset of symptoms. The control group consisted of 30 healthy subjects (23 women and seven men; the median age was 31 years, range 19–40), also described previously.6