Improving the Skin Prick Allergy Test: Exploring the Effect of Operator Dependent Factors on Test Variability; Social Factors Involved in the Lack of Public Awareness and Acknowledgement on Food Allergies in China

The prevalence of food allergies (FA) is on a rise globally, and a severe FA reaction can cause death-threatening anaphylaxis. Growing up in China, I have never acknowledged FA as a public health issue at risk of serious consequences. However, a few years of studying in the U.S. made me realize the importance of gauging the FA conditions in my surroundings, even though I was not personally affected. It is critical to approach FA through a public health lens and to engage in shared responsibilities to recognize it and prevent any adverse reactions. I wonder if there are any larger, underlying social factors in China that have contributed to, not just mine, but the lack of public awareness on FA as a public health issue, compared to a more informed societal response towards FA in the U.S. Channeling my interest in allergies, my technical project aimed to investigate the different operator-dependent variables involved in an allergy skin prick test (SPT), such as the applied force and angle, that contribute to the high inconsistency in test results, which lead to false positives and negatives. My capstone team’s goal is to provide more standardization for operator-dependent factors in SPT and to propose designs for a SPT device that inherently account for the effects of these variables, in an effort to reduce variability in test results and to improve accuracy and precision of SPT.
My capstone team found that, amongst the common SPT devices, Duotip, Greer Pick, and Stallerpoint, Duotip had the least overall variability in the volume of allergens delivered onto decellularized epidermis hydrogel from operators performing the tests. Afterwards, using Duotip, we investigated how operator-dependent factors, specifically different forces (0.007N, 0.036N, and 0.086N) and angles (35º, 45º, and 55º) applied, contribute to the variation in the allergen volume delivered by using Instron. There is no significant difference in the amount of allergens disposed between different force and angle conditions. Due to time constraints, we were unable to repeat trials despite unexpected limitations with the experimental design, because the forces of interest exceeded the Inston’s upperbound capacity, while the 55º condition failed to test properly due to collision between the Instron and the well plate containing hydrogel. Although the factor contributing to the majority of SPT result variability has not been identified with statistical significance, my team is considering improving experimental designs for future testing while designing a new SPT device that controls these operator-dependent factors to optimize standardization.
My STS research approached my question about the social factors attributed to the lack of public awareness on FA in China through the bottom two tiers of the Public Health Pyramid, focusing on socioeconomic factors and context for health, especially the accessibility and accuracy of key food allergen labeling in food services. I found that there are fewer studies in China than in the U.S. that systematically analyze the impact of socioeconomic factors on the lack of public awareness on FA. However, when analyzing the more available studies investigating the effects of socioeconomic factors on general allergy diseases in China, its prevalence is associated with higher individual socioeconomic status, whereas for a developed country as the U.S., the relationship between the two variables is inversely related, suggesting that the impact of socioeconomic factors on FA is more complex and dependent on the country’s level of economic development as a whole. Moreover, with respect to the policies for FA labeling on food items, the Standard in China ought to implement more supervised regulation on accurate FA labeling on foods for immediate consumption as well as manufacturers and food suppliers to caterers, while developing the list of key allergens according to varying regional and environmental FA prevalence.
The technical aspect focuses on how to increase the accuracy in allergy SPT results through more standardization towards operator-dependent variables and proposing new designs that inherently address the effects of these variables while promoting accessibility of SPT as well. Through a sociotechnical lens, standardizing an allergy diagnostic test, such as SPT, and device could encourage the general population to pursue early diagnosis of FA, leading to better prevention and timely medical management. In the meantime, gaining a deeper understanding of the social factors that contribute to the current limited public awareness and knowledge of FA in China is crucial. Given the environment-sensitive nature of FA prevalence, such insight can help different regions tailor their outreach efforts more effectively by developing educational programs, training, and resources to support the management of emergency FA reactions in public spaces.

School of Engineering and Applied Science

Bachelor of Science in Biomedical Engineering

Technical Advisor: Daniel Abebayehu

STS Advisor: William Davis

Technical Team Members: Ria Agrawal, Neda Rehan, Darius Walker