Organophosphate Pesticide Exposure Linked to Atopic Dermatitis Risk

New findings suggest that exposure to organophosphate pesticides (OPPs), especially dimethylphosphate, may be linked to an increase in atopic dermatitis risk among adults.1

These conclusions resulted from a recent analysis authored in part by YueHua Men, from the Peking University Third Hospital Department of Dermatology in Beijing. Men and colleagues noted that such pesticides are widely implemented as environmental chemicals and have potential effects on health, though a relationship with atopic dermatitis had been largely unclear prior to this study.

Additionally, Men et al. highlighted that the potential effects of OPPs on the development or exacerbation of different allergic conditions pose a notable public health concern necessitating exploration.2

“Based on previous evidence showing OPPs’ effects on immune function and inflammatory responses, we hypothesized that increased OPP exposure would be associated with higher [atopic dermatitis] risk, and this association might vary across different population subgroups due to variations in metabolic capacity,” Men and colleagues wrote. “This study aims to provide new clinical evidence for optimizing prevention strategies and treatment approaches for [atopic dermatitis].”1

The investigative team for the National Health and Nutrition Examination Survey (NHANES), a program which is representative of the US population and conducted by the National Center for Health Statistics (NCHS) under the Centers for Disease Control and Prevention (CDC), designed their assessment using a multistage, stratified probability sampling approach.

The analysis operates in biennial cycles to select representative samples from counties found across the country. In each cycle, the team includes extensive health and nutrition evaluations of those examined.

During their analysis of OPPs, the investigators utilized data from 4 NHANES cycles—1999–2000, 2001–2002, 2003–2004, and 2005–2007—based on the availability of concurrent information regarding atopic dermatitis and OPP metabolites. In their final sample, the publicly accessible dataset involved 4,258 participants during the team's analysis.

NHANES survey inquiries were used to determine atopic dermatitis, with self-reported responses employed within the NHANES questionnaires. There were a set of 3 specific questions from the Allergy and Dermatology Questionnaires implemented by the investigators, with all having been derived from standardized NHANES modules that had undergone rigorous validation as well as pretesting.

They used urinary concentrations of 6 dialkyl phosphate (DAP) metabolites as biomarkers of OPP exposure among study subjects. These metabolites included diethylphosphate (DEP), dimethylphosphate (DMP), dimethylthiophosphate (DMTP), dimethyldithiophosphate (DMDTP), diethylthiophosphate (DETP), and diethyldithiophosphate (DEDTP).

All of the investigative team's laboratory analyses were designed to adhere to NHANES’ standardized procedures and protocols related to quality control. The team also accounted for potential confounders in their analysis such as lifestyle factors (intake of alcohol, smoking status, and physical activity), demographic elements such as race, education level, sex, and poverty income ratio, subjects' dietary inflammatory index (DII), and chronic conditions such as hypertension and diabetes.

The investigators sought to ensure representativeness, applying NHANES sample weights, strata, and cluster variables in accordance with the study's complex sampling framework.

Within the study's fully adjusted models, it was noted by the investigators that a significant link was found between DMP (odds ratio [OR] = 1.17, 95% confidence interval [CI]: 1.05–1.31) and DMDTP (OR = 2.23, 95% CI: 1.08–4.60) and an increase in the odds of atopic dermatitis. The researchers' results of their weighted quantile sum (WQS) regression suggested that there was a significant link between mixed exposure to OPP and atopic dermatitis (OR = 1.25, 95% CI: 1.04–1.50).

Specifically, the team highlighted that DMP contributed the most (45.8%) to the cumulative mixture effect. In the study's sratified analyses, findings demonstrated that there were stronger associations among younger adults who were under 60 years of age, males, and those identified as smokers.

“While mechanistic studies are needed, these findings highlight the role of environmental factors in [atopic dermatitis] development and suggest targeted prevention strategies for susceptible populations,” the investigators wrote.1

Interested in dermatology? Learn more about the annual Revolutionizing Atopic Dermatitis (RAD) Conference, hosted by HCPLive Dermatology Times, and our CE/CME partner Physicians’ Education Resource.

References

1. Men Y, Wang Y, Wu W, Chu M. Association between organophosphate pesticide exposure and atopic dermatitis: a cross-sectional study based on NHANES 1999-2007. Front Public Health. 2025 Mar 6;13:1555731. doi: 10.3389/fpubh.2025.1555731. PMID: 40115349; PMCID: PMC11922850.

2. Corsini E, Sokooti M, Galli C, Moretto A, Colosio C. Pesticide induced immunotoxicity in humans: a comprehensive review of the existing evidence. Toxicology. (2013) 307:123–35. doi: 10.1016/j.tox.2012.10.009.