The epidemiology of atopic dermatitis and psoriasis in the indigenous people of Brazil

Abstract

The epidemiology of atopic dermatitis and psoriasis in the indigenous people of BrazilDear Editor, Atopic dermatitis (AD) and psoriasis have heterogeneous clinical presentations and both negatively impact quality of life. [1][2][3][4] We aimed to determine the prevalence of AD and psoriasis in a large Brazilian database created for the surveillance of morbidities and demographic data from Brazilian indigenous people.The Information Systems for Indigenous Health Care (SIASI) version 4.0, 5 a Brazilian national system responsible for grouping 34 Brazilian Sanitary Indigenous Districts (DSEI), was accessed in January 2023. We searched for active entries from the year 2022 that classified target diseases according to the International Classification of Diseases-10 (ICD-10) (Table 1). The diagnoses of AD and psoriasis were made between 2010 and 2022. For comparison purposes, we considered the infant mortality rate as a proxy for socioeconomic status. 6 According to the World Health Organization, infant mortality is classified into three groups: ≥50; from 20 to 49; and <20 infant deaths per 1000 live births.The Yanomami territory, the most remote indigenous area in Brazil, 7 was compared to the DSEIs situated in the Southeast and the South regions, in the most urbanized and developed states and cities of Brazil. 8 All prevalence rates were presented per 10,000 indigenous people. Statistical analysis was performed using R version 4.1.2 (R Core Team, Vienna, Austria). The study was approved by the Comissão Nacional de Ética em Pesqusisa (CONEP) (Reference code CAAE: 30638920.0.0000.0008).We examined data from 775,995 Brazilian indigenous people living in 34 DSEIS and found 15,055 people with AD and 953 with psoriasis. The period prevalence of AD in the total population was 194.0/10,000 (1.9%; 95% CI = 1.9%-1.9%) and for psoriasis it was 12.6/10,000 (0.1%; 95% CI = 0.1%-0.2%) patients (Table 2).For AD, most cases presented in children (n = 9987; 66.34%). The prevalence of AD in the Yanomami DSEI showed a significantly lower prevalence of AD in comparison to the DSEIs located near major urban centres in the Southeast and South regions of Brazil (p < 0.001; Table 2). Most cases of psoriasis were reported in adults (n = 525/55.1%). The Yanomami territory also had a lower prevalence of psoriasis than DSEIs