Background: Patch testing is the gold standard for diagnosing contact allergies, but its diagnostic accuracy can be influenced by subjective visual assessment and variability in measurement. Advanced imaging technologies, such as 3D imaging, may provide more reliable and objective methods for evaluating allergic reactions. Objective: This study evaluated the accuracy of the Iko Derma Monitor 3D imaging system in comparison to a standard clinic iPad for patch test reaction evaluation and to assess its potential advantages in documenting and interpreting allergic reactions. Methods: Forty-two patients undergoing patch testing for suspected contact allergy were included in this study, resulting in 293 evaluated reactions. Reactions were imaged on day 2 and day 4 using the Iko Derma Monitor, an iPad, and a handheld dermatoscope. Measurements of lesion area were summarized and compared across imaging modalities, and statistical tests were conducted to assess changes over time and accuracy difference between Iko Derma Monitor and iPad. Results: The 3D imaging device demonstrated significantly higher accuracy than the iPad when compared to the dermatoscope as the gold standard (p < 0.001). Both devices detected significant changes in lesion area over time, but the 3D device provided more consistent and sensitive measurements. T Conclusion: The Iko Derma Monitor 3D camera offers superior accuracy and sensitivity compared to iPad-based imaging for patch test reactions. This technology has the potential to improve diagnostic precision, particularly to distinguish irritant from borderline allergic reactions. Moreover, it may be useful in remote or underserved areas for enhancing access to patch testing and building the background for objective AI based evaluations.