Clinicoepidemiological Profile of Patients with Chronic Urticaria and its Association with D-dimer Levels at a Tertiary Care Centre: A Prospective Cohort Study

Abstract

Introduction: Chronic urticaria is a commonly encountered, long-standing skin condition that typically lasts for more than six weeks and has various underlying aetiologies, including chronic infections, infestations, immunological and non immunological causes, and physical factors. In some cases, it may be idiopathic. Recent studies have shown that the activation of the coagulation cascade is involved in the development of chronic urticaria. This involvement is reflected in plasma D-dimer levels, which are explored in the current study. Aim: To assess the epidemiological and clinical characteristics of urticaria and their association with D-dimer levels in a tertiary care centre. Materials and Methods: This prospective cohort study was conducted at Department of Dermatology, Great Eastern Medical School and Hospital, Srikakulam, Andhra Pradesh, India, from August 2022 to July 2023. The study included 100 chronic urticaria patients attending the dermatology Outpatient Department (OPD) to investigate various clinical types and their epidemiological factors. D-dimer levels were estimated using the latex-enhanced immunoturbidimetry assay method. The mean and range were calculated, and statistical analysis of various clinic-epidemiological characteristics was performed using Pearson’s Chi-square test. A p-value <0.05 was considered statistically significant. Results: Among the 100 patients with chronic urticaria, 40 (40%) were males and 60 (60%) were females. The mean age of presentation was 30 years, and the mean duration was 20.5 months. Elevated plasma D-dimer levels were noted in 40 (40%) of the study population. Chronic Spontaneous Urticaria (CSU) constituted 92 (92%) of the cases, followed by Chronic Inducible Urticaria (CIU) with 4 (4%) cases and 4 (4%) cases with CSU+CIU. Angioedema was noted in 20 (20%) of the cases in the present study. Thyroid disorder was seen in 12 (12%) of the study population. The majority of patients (44%) had mild urticaria. The mean Urticaria Activity Score (UAS) score before treatment was 21.08. A statistically significant association was found between elevated plasma D-dimer levels and age range, duration of chronic urticaria, disease severity, angioedema, and response to antihistamines. The response to antihistamines was graded based on the UAS7 score calculated before and after treatment. Conclusion: The present study provides additional evidence to the existing literature by establishing an association between D-dimer levels and factors such as severity and angioedema. It also provides important insights into the relationship between age range, duration of chronic urticaria, and elevated plasma D-dimer levels by establishing statistical significance between these factors.