Introduction
Urticaria is a common phenomenon that affects 15-25% of the population
at least once in a lifetime. While most episodes are acute1,2, a minority are prolonged, hence termed chronic
urticaria (CU). CU is defined as recurrent urticarial lesions, appearing
most of the days of the week, for at least 6 weeks.2-4The prevalence of CU in adults is estimated to be 1.8%, affecting women
more than men and with up to 50% remission rate within one to three
years.5 In adults, autoimmune or auto-allergy
mechanisms are suggested as possible etiologies for CU. In most
patients, no underline cause is found or can be proven, and the
urticaria is termed chronic spontaneous urticaria
(CSU).6
The literature regarding the characteristics and underlining mechanisms
of CSU in children is limited.2,5,7-14 It is estimated
that its prevalence in children is 0.1-0.3%15-18 with
an equal distribution between genders, except among
adolescents.5,13 However, a recent review demonstrated
1.1–1.5% prevalence of CU in children.19 The
remission rate of CSU in children after one year is reported to be low
(16.5% - 37%).2,5,18
A few small studies demonstrated an association between pediatric CSU
and atopic diseases, including asthma, allergic rhinitis (AR), atopic
dermatitis (AD) and food allergy.5,8-10 An overall,
coexisting prevalence of 30% to 50% has been
described.5,10,13 Chansakulporn et al. followed a
small group of 92 patients and reported that one-third of the children
with CU had atopic diseases, with an unusually high prevalence of food
allergy (15.2%).5 Netchiporouk et al. reported that
28% of 139 children with CSU had atopy, but they did not distinguish
between the different types of atopic diseases and age
groups.9 In addition to atopic diseases, autoimmune
diseases, including thyroid diseases, celiac and systemic lupus
erythematosus (SLE) were also found to be associated with CU in
children.20,21,22
The aim of the current study was to describe the demographics, clinical
characteristics, comorbidities, and outcomes of a large pediatric cohort
with CSU.