3096 Clinical Spectrum and Natural History of Chronic Urticaria in Hong Kong Children

Friday, 16 October 2015
Hall D1 Foyer (Floor 3) (Coex Convention Center)

Agnes Sze-Yin Leung, MBChB , Department of Paediatrics, The Chinese University of Hong Kong, Hong Kong, Hong Kong

Ting Fan Leung, MD, FRCPCH, FAAAAI , Department of Paediatrics, Prince of Wales Hospital, Hong Kong, Hong Kong

Background: Chronic urticaria (CU) lasting for 6 weeks or longer can be classified into chronic spontaneous urticaria (CSU), urticarial vasculitis, and inducible (physical) urticaria. A cause for CSU is not identified in approximately 60% of patients. Thirty to 50 percent of adults with CU achieved remission 1-3 years after onset. This study investigated the clinical spectrum and natural course of CU in Chinese children and identified possible predictors of disease remission.

 Methods: This single-centre retrospective study identified 96 patients with CSU below 18 years of age who were followed in our allergy clinic for  6 months. Disease-related factors such as occurrence of urticaria, angioedema and anaphylaxis as well as familial history, environmental exposures, co-morbid allergies, immunological investigations and drug treatments were retrieved from medical records. Patients were considered to be in remission when they were symptom-free for  3 months. Natural history of CU was delineated by Kaplan-Meier analysis, and factors associated with disease remission were analysed by log-rank statistics.

 Results: The mean (SD) age of patients at baseline was 9.0 (5.2) years, and 53 (55%) of them were male. They were followed for a median of 4.0 years. Coexisting asthma, rhinitis and eczema affected 47%, 51% and 24% of these patients. Sixty-seven percent (53/79) of patients were atopic. Forty-seven (49%) patients had urticarial episodes at least once weekly, and 33 patients had both urticaria and angioedema. Both patients who developed anaphylaxis (one respiratory and one cardiorespiratory) had persistent disease. Seventy-nine patients had concomitant inducible urticaria. Laboratory investigations revealed positive anti-nuclear antibody in 26% (12/47; none with anti-thyroid antibodies), circulating eosinophilia in 24% (14/59), increased serum total IgE in 68% (40/59) and low plasma C3 and/or C4 levels in 30% (16/53). Fifty-six patients were treated with non-sedating antihistamines alone and 15 had combined non-sedating antihistamines and H2 antagonists. Sixty (63%) patients were in remission at a median of 2.4 years from disease onset. None of the clinical and laboratory parameters was associated with disease remission.

 Conclusions: Childhood CU has in general favourable prognosis, and two-thirds of them achieve disease remission. This study cannot identify any clinical or laboratory factor for the resolution of CU.

 Funding: Direct Grant for Research (2013.2.033), CUHK