Abstract : <p>Chronic urticaria (CU) is a common dermatological condition that may occur spontaneously or may be induced by specific triggers. Heat shock proteins (HSPs) are molecular chaperones with critical roles in protein synthesis. They are induced in response to physiological and environmental stressors. The present study aimed to investigate the relation between serum levels of HSP-70 and severity of chronic urticaria. The present case control study included 70 patients with chronic spontaneous urticaria (CSU). In addition, there were 25 age and sex-matched healthy control. The severity of their urticaria symptoms were assessed using Urticaria Activity Score (UAS). Symptoms were classified as mild, moderate or intense. Serum levels of HSP70 measured by ELISA method. Patients had significantly higher HSP-70 levels when compared with controls [median (IQR): 62.0 (0.23-0.91 versus 0.26 (0.2-0.45) ng/ml, p0.001] (Fig. 1). Patients group included 29 patients (41.4 %) with mild disease, 29 patients (41.4 %) with moderate disease and 12 patients (17.2 %). Comparison between patients with different disease severity grades shows signification relation between disease severity grade and HSP-70 levels. Logistic regression multivariate analysis identified elevated HSP-70 levels as significant predictor of significant (moderate/intense) CU. The present study found a significant relation between increased serum HSP-70 levels and increased disease severity in CU patients.</p>