Comorbidities
A total of 87 patients (34.8%) had at least one atopic disease (Figure 1A): in 64.4% (56/87) the diagnosis of atopic disease was established before or concurrently with CSU. The atopic comorbidities found in the study cohort were: AD (n=43, 17.2%), AR (n=40, 16.1%), asthma (n=33, 13.3%) and food allergy (n=8, 3.2%). Thirty patients (12%) had more than one atopic co-morbidity. After excluding the patients diagnosed with AD, the prevalence of atopic comorbidities did not differ significantly: AR (n=27, 13% vs. 16.1% in the total cohort, p=0.36), asthma (n=21, 10.1% vs. 13.3% in the total cohort, p=0.3) and food allergy (n=7, 3.4% vs. 3.2% in the total cohort, p=0.9). Consequently, the rest of the analyses are presented for the entire group.
No correlation was found between the prevalence of AR, AD, asthma, or food allergy and the duration of CSU. Furthermore, there was no difference in the probability of relapse and the presence of atopic disease as a co-morbidity (9.8% vs. 9.2%, p=0.87).
The prevalence of the different atopic diseases in CSU patients and the general pediatric population in Israel and in the world was compared (Figure 1B): The prevalence of AD in two age groups (4-8 years and 13-18 years) of the study population was significantly different compared to the general population in Israel7,23,24 and in the world25 (p<0.01). Differences in the prevalence of allergic rhinitis were statistically significant only in adolescents when compared to the general population of adolescents in Israel7,23,26 and in the world27(p<0.01). The differences in the prevalence of food allergy between participants in the current study and the general world population28,29 were statistically significant in children age 4-8 years (p<0.05) but did not reach significance when compared to adolescents in the current study and adolescents in Israel7,30 (p=0.83). Differences in the prevalence of asthma between the current study and the general population in Israel7,24,26 and in the world 31did not reach significance in any age group (p=0.46–0.99).
Overall, 18 patients (7.2%) had a concomitant autoimmune disease compared to 1.9% in the general adolescent population in Israel (p<0.01). Nine (3.6%) were diagnosed with thyroid disease, 7 with hypothyroidism and 2 with hyperthyroidism. Psoriasis was found in 6 patients (2.4%), type I diabetes mellitus in 2 patients (0.8%) and 1 patient was diagnosed with juvenile rheumatoid arthritis (0.4%). Celiac disease, irritable bowel disease and SLE were not diagnosed in our cohort. IBS was diagnosed in 5 patients (2%).
Seven patients (2.8%) had psychiatric disorders, including depression, anxiety, bipolar disorder, and schizophrenia. All were diagnosed after the first CSU episode.