Risk Factors for Acute Urticaria in Central California

Abstract

At least 15–20% of the population in the world suffers from urticaria. Allergy triggers contribute to the development of urticaria. Not much is known about the demographic and environmental risk factors that contribute to the occurrence of acute urticaria. Methods: We utilized emergency department data on acute urticaria-related visits managed by the California Office of Statewide Planning and Operations for 201 zip codes located in southern central California (San Joaquin Valley) collected during the years 2016 and 2017. Census data from the same zip codes were considered as a population at risk. Socioeconomic and environmental parameters using CalEnviroScreen (Office of Environmental Health Hazard Assessment, Sacramento, CA, USA) database for the zip codes were evaluated as risk factors. Results: The incidence rate of acute urticaria in San Joaquin Valley during 2016–2017 was 1.56/1000 persons (n = 14,417 cases). Multivariate Poisson analysis revealed that zip codes with high population density (RR = 2.81), high percentage of farm workers (RR = 1.49), and the composite of those with high and medium percentage of poverty and those with high and medium percentage of non-white residents (RR = 1.59) increased the likelihood of the occurrence of acute urticaria. Conclusion: High population density, farm work, poverty and minority status is associated with a high risk of having acute urticaria.

Urticaria

“…All ethnicities are affected; however, the prevalence of AU and CU was higher in non-white patients in some studies 15,19,22 but not all 23 . The lifetime prevalence of all types of urticaria and AU is 3-22% and 6-19%, respectively (see Supplementary Table 5).…”

“…However, each urticaria subtype has its own prevalence within different populations. The prevalence of AU is highest in children <5 years of age [14][15][16] , whereas CU, especially CSU, is most prevalent in women >30 years old 6, [17][18][19][20][21] . Adult patients with CSU are older than adult patients with CIndU (average age ~30-70 years versus ~20-40 years) and have older age of disease onset (~30-50 years versus ~20-35 years).…”

“…Risk factors reported for AU include high population density 15 and personal 32 and parental history of allergic diseases 2,33 . Higher prevalence and/or higher risk of having AU may be associated with poverty and lower socio-economic status 14,15 , whereas risk for CU was linked to high income and socio-economic status in some studies 2, 23,34 but not all 35,36 . In studies involving twins, genetic factors could partly explain susceptibility to urticaria 32 .…”

Global, regional, and national levels and trends in burden of urticaria: a systematic analysis for the global burden of disease 2019 study

“…(36) But there also are experiments that, contrary to our conclusions, demonstrating that individuals from regions with a higher poverty percentage exhibit a higher risk of urticaria visits. (37) For such differences, several reasons are posited: Firstly, reporting bias: regions with high SDI often have advanced healthcare systems, potentially increasing the diagnostic rates for urticaria, thereby increasing prevalence and incidence rates. In regions with low SDI, many cases may remain unreported or undiagnosed due to inadequate diagnostic facilities or lack of public awareness.…”

Air pollution and emergency department visits for urticaria

“…A recent study showed that applying a topical antioxidant may help reduce the effect of ozone-induced oxidation on the skin [16]. Other risk factors such as high population density, farm work, poverty and minority status have all been shown to be associated with an increased risk of developing urticaria [17,18]. While this study shows quite a strong association between air pollution (and in particular ambient ozone) and urticaria, some studies found little or no association between development of urticaria and air pollution [19] and associated the higher rates of urticaria to food allergies and other factors.…”