Risk factors of uncontrolled symptoms using the standard dose of second-generation H1-antihistamines in chronic spontaneous urticaria children

Background: A standard dose of second-generation H1-antihistamines is recommended as the first-line treatment of chronic spontaneous urticaria (CSU), previous studies have found that approximately 20-50% of CSU children fail to control their symptoms and required step-up treatments. Objective: To evaluate the predictors of uncontrolled symptoms with first-line medication and describe the treatment outcomes of CSU children in the southern region of Thailand. Methods: This retrospective chart review of CSU patients, aged 2-18 years, who were initially treated with the standard dose of second-generation H1-antihistamine at the Pediatric Allergy Clinic, Songkhlanagarind Hospital, from January 2008 to July 2018. The data were collected at the initial visit (demographic data, onset of rash, frequency of urticaria, presence of angioedema, previous resolved CU, laboratory investigation results) and follow-up visits (treatment out -come, time to controlled urticaria). Results: The medical records of 192 CSU children were reviewed; their median age were 8.5 years and the mean fre-quency of rash was 4 days/week. Forty-seven children (24.4%) fail to controlled symptoms with a standard dose of second-generation H1-antihistamines and a factor significantly associated was frequency of rash for more than 4 days per week (OR = 4.36, P < 0.001). The median time to controlled urticaria was 1.28 months. Conclusions: Most of CSU children in the southern region of Thailand experienced controlled symptoms with a stan-dard dose of second-generation H1-antihistamines, and the frequency of urticaria for more than 4 days per week was a factor associated with uncontrolled symptoms that regimen.