Global Epidemiology of Urticaria: Increasing Burden among Children, Females and Low-income Regions.

Urticaria has a high socioeconomic burden worldwide. However, the global epidemiology of urticaria and its geographical and temporal trends are not well studied. Using the Global Burden of Disease dataset, the aim of this study was to analyse the age-standardized prevalence, incidence, years lived with disability, and mean duration of urticaria in 195 countries from 1990 to 2017. In addition, the relationship between socioeconomic development and urticaria was evaluat-ed. The global prevalence of urticaria in 2017 was 86 million people. Females and children aged 1-4 years were more commonly affected than males and adults, respectively: these differences were outside the 95% uncertainty intervals. Regression analyses show-ed that a lower gross domestic product per capita was associated with a higher prevalence and incidence of urticaria (p < 0.001). The global prevalence of urticaria, incidence, and years lived with disability have remained stable from 1990 to 2017.

Cutaneous delayed-type hypersensitivity in patients with atopic dermatitis: reactivity to topical preservatives.

BACKGROUND: Patients with atopic dermatitis (AD) have chronic dry skin to which they frequently apply skin care products containing preservatives, and they are predisposed to developing cutaneous delayed-type hypersensitivity. OBJECTIVE: We sought to compare the rates of positive patch test reactions to allergens on the North American Contact Dermatitis Group (NACDG) standard tray among patients with and without AD and to assess whether atopic patients in our database were more likely to patch test positive to preservatives. METHODS: A total of 2453 patients underwent patch testing to the NACDG standard screening series. The incidence of positive patch test reaction among patients with AD (n = 342) and without AD (n = 2111) was assessed. Statistical analysis was done using a χ(2) test. RESULTS: Compared with nonatopic patients, patients with AD were statistically more likely to have positive patch tests. AD was associated with contact hypersensitivity to quaternium-15, imidazolidinyl urea, DMDM hydantoin, and 2-bromo-2-nitropropane-1,3-diol but not to parabens, formaldehyde, or diazolidinyl urea. LIMITATIONS: Only patients suspected of having allergic contact dermatitis were tested. Our population was geographically limited to metropolitan Kansas City, MO, and metropolitan New York City, NY. CONCLUSIONS: Patients with AD should avoid the use of skin care products preserved with formaldehyde releasers.

Cutaneous delayed-type hypersensitivity in patients with atopic dermatitis: reactivity to surfactants.

BACKGROUND: Patients with atopic dermatitis (AD) have abnormalities in skin barrier function, and are predisposed to developing cutaneous delayed-type hypersensitivity. Soap and detergents are known to exacerbate the breakdown of the skin barrier. OBJECTIVE: We sought to assess whether atopic patients in our database were more likely than nonatopic patients to patch test positive to the surfactants cocamidopropyl betaine (CAPB) and cocamide diethanolamide (DEA), or to the surfactant precursor amidoamine. METHODS: Between January 1, 2001, and the present, a total of 1674 patients underwent patch testing to the North American Contact Dermatitis Group standard screening series. The incidence of positive patch test results to CAPB, cocamide DEA, and amidoamine among patients with AD (n = 242) and without AD (n = 1422) was assessed. Statistical analysis was done using a χ(2) test. RESULTS: AD was associated with contact hypersensitivity to CAPB, but not to cocamide DEA or amidoamine. LIMITATIONS: This was a retrospective study of patients evaluated for suspected allergic contact dermatitis and, therefore, matching for gender, age, or other parameters was not possible. Our population was geographically limited to metropolitan Kansas City, MO, and metropolitan New York City, NY. CONCLUSIONS: Patients with AD should avoid the use of skincare products containing the surfactant CAPB.

Cutaneous Delayed-Type Hypersensitivity to Surfactants.

BACKGROUND: Repeated and prolonged use of surfactants can cause irritant as well as allergic contact dermatitis. OBJECTIVE: This study reports the frequency of positive patch test results to surfactants tested on the North American Contact Dermatitis Group screening series including cocamidopropyl betaine (CAPB), amidoamine (AA), dimethylaminopropylamine (DMAPA), oleamidopropyl dimethylamine (OPD), and cocamide diethanolamide (CDEA), and correlations of positive reactions between CAPB and the other surfactants. METHODS: This was a retrospective analysis of 10 877 patients patch tested between 2009 and 2014 to the surfactants CAPB, AA, DMAPA, OPD, and CDEA. Frequencies of positive reactions to these surfactants were calculated, and trends of reactivity between the surfactants analyzed. CONCLUSIONS: The OPD had the highest rate of positive patch reactions (2.3%) followed by DMAPA (1.7%), and CAPB (1.4%). The AA and CDEA had the lowest rate of positive reactions (0.8%). There was a high degree of overlap in positive patch tests between the surfactants. The CDEA was the least likely to coreact with another surfactant.