Prevalence and Risk Factors of Urticaria With a Focus on Chronic Urticaria in Children

Abstract

Purpose: Limited data is available on the prevalence and risk factors of acute and chronic urticaria in children. Our purpose was to determine the prevalence and identify the risk factors of acute and chronic urticaria in Korean children.

Methods: This population-based study examined 4,076 children (age 4 to 13 years) who were enrolled in the 2015 prospective Seongnam Atopy Project (SAP 2015) in Korea. The parents completed an urticaria questionnaire that included questions regarding the duration, severity, and triggering factors of urticaria. Blood sampling (n=464) was performed to measure vitamin D, total eosinophil count (TEC), and total IgE levels, and skin prick tests (n=503) were done.

Results: The prevalences of the life-time, acute, and chronic urticaria were 22.5%, 13.9%, and 1.8% (chronic continuous urticaria, 0.7%; and chronic recurrent urticaria, 1.1%), respectively. Acute urticaria was significantly associated with allergic diseases and parental history of allergy (P<0.001), but chronic urticaria was not associated with these clinical factors. There was no significant difference in the 25-hydroxyvitamin D level between subjects with chronic urticaria and controls (P=0.124). Chronic continuous urticaria was associated with living in a new residence (aOR=2.38, 95% CI=1.02-5.54, P=0.044) and belonging to a family with a high income (aOR=4.24, 95% CI=1.24-14.56, P=0.022).

Conclusions: A total of 1.8% of children were found to have chronic urticaria. Living in a new residence and belonging to a family with a high income increased the risk of chronic continuous urticaria.

Keywords: Acute urticarial; chronic urticarial; prevalence; risk factor, urticaria.

Fig. 1. Enrolment and classification of children (4 to 13 year-old) who reported having had wheals or angioedema at some time during their lifetimes (n=917, 22.5%) and controls (n=3,159, 77.5%).

Fig. 2. Urticaria activity scores (UAS; mild, moderate, and intense) of subjects with chronic and acute urticaria. The maximum UAS for wheals was significantly higher for individuals with chronic urticaria than for those with acute urticaria (1.7±0.8 vs 1.3±0.7, P=0.007), but there was no significant difference for pruritus (acute: 2.6±0.9, chronic: 2.7±1.1, P=0.515).

Fig. 3. Causes of acute and chronic urticaria. The most common tentative causes were food (n=236, 37.8%) and changing environment (n=172, 27.6%). Cold exposure was the only factor significantly different for subjects with chronic and acute urticaria (14% vs 6.7%, P=0.043).