Chronic Urticaria remains a major problem in terms of etiology, investigation, and management. Chronic spontaneous urticaria affects 0.5-1% of individuals (lifetime prevalence) and significantly reduces quality of life (QOL). Aims of the Study: 1) To evaluate the types of chronic urticaria with reference to etiology from history and investigations. 2) To identify the specific cause of urticaria by thorough history and investigations. Materials and Methods: Out of 300 patients with chronic spontaneous urticaria were enrolled. Autologous serum skin test (ASST) was performed after excluding physical urticaria. Routine laboratory tests were performed after ASST in all patients; and other specific investigations were done where necessary. Skin prick test was done in idiopathic urticaria. Results: Out of 300 patients, 100 (33%) had history of angioedema. Out of 300 patients, auto-immune condition was present in 48 (16%) patients. Provocating factors were present in 81 (27%) patients. In our study 123 (41%) patients showed infective focus on routine screening investigation. ASST was positive in 60% of patients. Physical urticaria were found in 47 (15.66%) patients by challenge test, most common was dermographism. In prick test, maximum number of patients reacted positively to food allergens followed by pollen, dust, fungus in decreasing frequency. Conclusion: Nearly half of the patients had chronic autoimmune urticaria on the basis of ASST. Chronic spontaneous urticaria requires extended diagnostic measures based on the patient’s history.

Keywords: Auto antibodies; Autoimmune disease; ASST; CSU; Skin prick test.