Urticaria is a common cutaneous vascular reaction pattern caused by diverse and multiple factors. However, an etiologic factor can be established in less than 20% of chronic cases. In this study, 274 patients with urticaria were evaluated in the dermatology clinic of King Fahd Hospital of the University (KFHU) between 1989 and 1992. Saudi nationals predominated; 188 patients were males (68.6%) and 86 were females (31.4%) and the peak incidence of urticaria was in young adults. The incidence of urticaria was 3.79% of dermatological cases. The success rate for identification of etiological factors was 41% in acute urticaria and 14% in chronic urticaria. The etiological categories discovered included allergies, physical factors, infections and miscellaneous systemic factors. In conclusion, causative factors remained elusive in the majority of cases. The identification and removal of the possible causative factors is the most important aspect of management in urticaria. A detailed history and physical examination are in order; however, extensive laboratory investigations are unnecessary. Ann Saudi Med 1995;15(1):10-13. MAE Uthman, M El-Nuhd, Experience in Urticaria with Patients Attending a Dermatological Clinic in a Referral Center in the Eastern Province of Saudi Arabia. 1995; 15(1): 10-13Urticaria is a common cutaneous eruption characterized by evanescent, pruritic and slightly erythematous plaques or papules. The incidence of urticaria has been estimated to vary from 10% to 25% in the general population.1 Urticaria is a vascular reaction pattern which can be caused by multiple and diverse factors. These factors activate mast cells as well as other cells (e.g., eosinophils, basophils, neutrophils, endothelial cells and platelets) with the release of their vasoactive and chemotactic mediators of inflammation. 2,3 Histamine is the best known mediator of increased vascular permeability and itching in urticaria; however, serum factors, kinins, fibrin degradation products, leukotriens and various enzymes have also been recognized to play a pathogenic role in urticaria. 3,4 Therefore, the pathogenetic mechanism involved in urticaria can be classified as either immunological or nonimmunological reactions. 5,6 In clinical practice, an urticarial eruption can easily be diagnosed; however, finding the etiological factor(s) involved can be difficult and impossible in the majority of cases.7 To the best of our knowledge, reports of urticaria from the Middle East and in particular from Saudi Arabia are unavailable. This study was undertaken to highlight the prevalence of urticaria and to evaluate its etiological factors involved in patients referred to our dermatology clinic. Patients and MethodsWe interviewed and reviewed all patients with urticaria seen consecutively at the dermatology clinic of King Fahd Hospital of the University (KFHU) in Al-Khobar from 1989 to 1992. The number of patients forming the basis of our statistical analysis was 274 and the case records of 34 patients were excluded for either an incorrect or a ...