A Hospital Based Study of Association of Chronic Spontaneous Urticaria with Autologous Serum Skin Test

Abstract

Introduction: Chronic Spontaneous Urticaria (CSU), is spontaneous occurrence of wheals for more than 6 weeks. CSU patients with autoreactivity as indicated by positive Autologous serum skin test (ASST) have severe disease requiring higher doses of antihistamines and even immunomodulatory agents.

Objective: The objective of this study was to observe the association between CSU and ASST.

Materials and Methods: Over a period of one year, 104 CSU patients were enrolled in the study. Autologous serum skin test was done using 0.05 ml of patient’s serum, with 0.05 ml of histamine as positive control and normal saline as negative control. Prevalence of positive ASST in CSU patients was determined. Clinical and demographic characteristics were compared in both ASST positive and negative patients.

Results: The ASST was positive in 68 patients (65.4%). Mean age (SD) of the patients in ASST positive group was 33.78 (14.38) versus 35.64 (14.47) in ASST negative group (p=0.533). Male:Female ratio in ASST group was 1:2.7 versus 1:1.1 in ASST negative group (p=0.033). Patients with positive ASST had significantly longer duration of wheals (p=0.002), generalized distribution (p=0.020) and high rmean urticaria activity score, 4.66 versus 3.28 in ASST negative patients, p<0.001. Angioedema was more common in ASST positive patients (p < 0.001).

Conclusion: ASST was significantly positive in CSU patients and more common in females. ASST positive patients had more severe clinical manifestations and it can be a simple test to detect severe form of CSU.