Background:Chronic urticaria (CU) is a skin disorder characterized by the recurrent appearance of wheals and/or angioedema for at least 6 weeks. CU is a heterogeneous disorder which includes chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CIU).
Objective:To study the pattern of chronic urticaria among the patients attending dermatology outpatient clinic in Sohag University Hospitals and to study the association between the results of autologous serum skin test (ASST) and urticaria severity score (USS)and to detect serum level of anti IgE receptors antibodies using ELISA.
Results:ASST  was positive in 41 (38 %) patients andthere was a statistically significant relation between ASST result and duration of the disease  (p value 0.014).22 (20.4%) of the patients had mild score , 50 (46.3%) had moderate score and 36 (33.3%) had severe score. The relation of USS to the positivity of ASST was statistically significant (p value 0.000).The mean of anti IgE receptor antibodies in ASST positive group was more than that of those negative ones that was highly statistically significant ( P value 0.000).
Conclusion:ASST remains a baseline diagnostic test for CAU. Patients with CAU had more frequent attacks and longer duration than other types of chronic urticaria.